Semi disposable auto injector

ABSTRACT

An automatic injection device including a reusable driving assembly having a forward injection end and an engagement element and a disposable cassette assembly including an injectable liquid to be injected at an injection site, wherein the disposable cassette assembly is removably insertable into the reusable driving assembly at the forward injection end and is removably retained within the reusable driving assembly by snap fit engagement therewith, the snap fit engagement being effected at least partially by the engagement element, which is displaced rearwardly by insertion of the disposable cassette assembly in the reusable driving assembly.

REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No.PCT/IL2015/050155 filed Feb. 10, 2015, claiming priority based on U.S.Provisional Patent Application No. 61/937,681, filed Feb. 10, 2014, thecontents of all of which are incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The present invention generally relates to an auto injector, and morespecifically to a semi disposable and safe auto-injector adapted forparenteral administration of substances (e.g., a medication) to a livingorganism (human or animal).

BACKGROUND OF THE INVENTION

As many as ten percent of patients may experience needle phobia, acondition recognized by the American Psychiatric Association, and may behesitant to inject themselves (J. Hamilton, “Needle Phobia: a NeglectedDiagnosis.” Journal of Family Practice, 1995; 41:169-175).

Moreover, in the U.S., a recent law requires health care employers toimplement “safer medical devices” to minimize needle sticks that couldresult in serious infections (such as HIV and Hepatitis) from viruses orbacteria in the blood. Interest in safety-needle protective devices isnow increasing in all areas of healthcare. A particular drug may be usedin various care settings.

SUMMARY OF THE INVENTION

The present invention seeks to provide a semi disposable auto injector.

There is thus provided in accordance with a preferred embodiment of thepresent invention an automatic injection device including a reusabledriving assembly having a forward injection end and an engagementelement and a disposable cassette assembly including an injectableliquid to be injected at an injection site, the disposable cassetteassembly is removably insertable into the reusable driving assembly atthe forward injection end and is removably retained within the reusabledriving assembly by snap fit engagement therewith, the snap fitengagement being effected at least partially by the engagement element,which is displaced rearwardly by insertion of the disposable cassetteassembly in the reusable driving assembly.

Preferably, the disposable cassette assembly includes a needle guardelement having arms formed with notches, the engagement element is aneedle guard deploying element, having fingers formed with inwardlydirected protrusions, and the insertion of the disposable cassetteassembly into the reusable driving assembly produces rearwarddisplacement of the needle guard deploying element, thereby enablingengagement of the inwardly directed protrusions of the needle guarddeploying element with the notches of the arms of the needle guardelement.

Preferably, the reusable driving assembly also includes a needle guarddeploying spring, the arms have rearward facing edges, the needle guarddeploying element has a forward-facing surface and the rearwarddisplacement of the needle guard deploying element causes engagement ofthe rearward facing edges of the arms of the needle guard element of thedisposable cassette assembly with the forward facing surface of theneedle guard deploying element, against the urging of the needle guarddeploying spring.

Further preferably, the reusable driving assembly has at least cockedand uncocked operative orientations, the reusable driving assemblyincludes a safety catch element having engaged and disengaged operativeorientations and the snap fit engagement occurs only when the reusabledriving assembly is in the cocked operative orientation and when thesafety catch element is in the engaged operative orientation.

In accordance with a preferred embodiment of the present invention thedisposable cassette assembly includes a cassette housing element, asyringe including a needle, and a needle guard element. The cassettehousing element, the syringe and the needle guard element being arrangedsuch that prior to insertion of the disposable cassette assembly intothe reusable driving assembly, the syringe is locked against axialdisplacement in a first direction relative to the cassette housingelement by engagement with the cassette housing element and is lockedagainst axial displacement in a second direction, opposite to the firstdirection, relative to the cassette housing element by engagement withthe needle guard element.

Preferably, the syringe is a prefilled syringe.

In accordance with a preferred embodiment of the present invention thereusable driving assembly has a needle insertion operative orientation.The cassette housing element, the prefilled syringe and the needle guardelement are arranged such that subsequent to insertion of the disposablecassette assembly into the reusable driving assembly but prior to thereusable driving assembly being in the needle insertion operativeorientation, the prefilled syringe is locked by the cassette housingelement and the needle guard element against axial displacement ineither direction relative to the cassette housing element, but thesyringe is not locked against axial displacement relative to the needleguard element at at least some other times.

Preferably, when the reusable driving assembly is in the needleinsertion operative orientation, the syringe moves axially forwardlytogether with the cassette housing element relative to the needle guardelement, thereby exposing the needle at the forward injection end of thereusable driving assembly.

Further preferably, the cassette housing element and the needle guardelement are arranged such that prior to both the disposable cassetteassembly having been inserted into the reusable driving assembly and thereusable driving assembly being in the needle insertion operativeorientation, the relative axial displacement between the cassettehousing element and the needle guard element is prevented.

In accordance with a preferred embodiment of the present invention thecassette housing element is arranged such that upon the reusable drivingassembly being in a needle insertion operative orientation, resultingaxial displacement of the syringe produces outward displacement of aportion of the cassette housing element into engagement with a forwardbase element of the reusable driving assembly, thereby limiting thepenetration depth of the needle.

Preferably, the reusable driving assembly includes a forward injectionend and multiple mutually axially displaceable elements, the needle issuitable for injecting an injectable liquid at an injection site, thedisposable cassette assembly is removably insertable into the reusabledriving assembly at the forward injection end and following insertion ofthe disposable cassette assembly into the reusable driving assembly, theautomatic injection device may be caused to assume an injection siteengagement operative orientation by pressing the forward injection endof the reusable driving assembly against the injection site, therebyproducing mutual axial displacement of at least some of the multiplemutually axially displaceable elements but not producing relative axialdisplacement between the needle guard element and the cassette housingelement of the disposable cassette assembly.

Further preferably, following insertion of the disposable cassetteassembly into the reusable driving assembly, the automatic injectiondevice may be caused to assume an injection site engagement operativeorientation, following assumption of the pre-needle insertion operativeorientation, the automatic injection device may be caused to assume aneedle insertion operative orientation by pressing the trigger buttonelement, thereby causing forward axial displacement of the cassettehousing element and resulting penetration of the injection site by theneedle to a penetration depth defined by engagement of the cassettehousing element with the forward base element of the reusable drivingassembly.

In accordance with a preferred embodiment of the present inventionfollowing injection the disposable cassette assembly extends partiallyoutside of the reusable driving assembly at the forward injection endand is releasably retained in the reusable driving assembly and thedisposable cassette assembly may thereafter be fully disengaged from thereusable driving assembly by axially pulling the disposable cassetteassembly out of the reusable driving assembly.

Preferably, only following insertion and retention of the disposablecassette assembly in the reusable driving assembly, the automaticinjection device may be caused to assume a needle insertion operativeorientation by pressing the trigger button element, thereby causingforward axial displacement of the cassette housing element and resultingpenetration of the injection site by the needle.

Further preferably, the reusable driving assembly includes a plungerelement, a forward cover element and a rearward cover element, a springand at least one cocked orientation retaining element operative in acocked operative orientation of the reusable driving assembly forcocking the plunger element against the urging of the spring andretaining the plunger element in the cocked operative orientation.

In accordance with a preferred embodiment of the present invention theforward cover element and the rearward cover element move towards eachother in assuming the cocked operative orientation and when in thecocked operative orientation are locked against mutual axialdisplacement.

Preferably, the disposable cassette assembly includes a cassette housingelement, a prefilled syringe including a needle for injecting aninjectable liquid at an injection site and a needle guard element, andfollowing injection and removal of the needle from the injection site,assumption of the cocked operative orientation is possible thereafteronly following forward displacement of the needle guard element relativeto the needle.

Still preferably, the reusable driving assembly includes a forwardinjection end, a safety catch element and a trigger button element, theautomatic injection device may be caused to assume a needle insertionoperative orientation by pressing the trigger button element, therebycausing forward axial displacement of the cassette housing element andresulting penetration of the injection site by the needle, only when allof the following conditions are met: the reusable driving assembly is ina cocked operative orientation, the disposable cassette assembly isinserted and retained in the reusable driving assembly, and the safetycatch element is in a disengaged operative orientation.

Yet preferably, the automatic injection device may be caused to assume aneedle insertion operative orientation by pressing the trigger buttonelement, thereby causing forward axial displacement of the cassettehousing element and resulting penetration of the injection site by theneedle, only when all of the following conditions are met: the reusabledriving assembly is in a cocked operative orientation; and thereafterthe disposable cassette assembly is fully inserted and retained in thereusable driving assembly, and thereafter the safety catch element is ina disengaged operative orientation.

There is also provided in accordance with another preferred embodimentof the present invention, a disposable cassette assembly for use with areusable driving assembly in an automatic injection device, thedisposable cassette assembly including a cassette housing element, asyringe including a needle and a needle guard element. The cassettehousing element, the syringe and the needle guard element being arrangedsuch that prior to insertion of the disposable cassette assembly intothe reusable driving assembly, the syringe is locked against axialdisplacement in a first direction relative to the cassette housingelement by engagement with the cassette housing element and is lockedagainst axial displacement in a second direction, opposite to the firstdirection, relative to the cassette housing element by engagement withthe needle guard element.

Preferably, the syringe is a prefilled syringe.

Further preferably, the reusable driving assembly has a needle insertionoperative orientation. The cassette housing element, the prefilledsyringe and the needle guard element are arranged such that subsequentto insertion of the disposable cassette assembly into the reusabledriving assembly but prior to the reusable driving assembly being in theneedle insertion operative orientation, the prefilled syringe is lockedby the cassette housing element and the needle guard element againstaxial displacement in either direction relative to the cassette housingelement, but the syringe is not locked against axial displacementrelative to the needle guard element at at least some other times.

In accordance with a preferred embodiment of the present invention thecassette housing element and the needle guard element are arranged suchthat prior to both the disposable cassette assembly having been insertedinto the reusable driving assembly and the reusable driving assemblybeing in the needle insertion operative orientation, the relative axialdisplacement between the cassette housing element and the needle guardelement is prevented.

Preferably, the disposable cassette has a pre-use operative orientation,which is suitable for storage thereof and in the pre-use operativeorientation, the needle guard element is locked to the cassette housingelement by snap fit engagement of protrusions of the needle guardelement in slots formed in the cassette housing element.

There is further provided in accordance with yet another preferredembodiment of the present invention a reusable driving assembly having aneedle insertion operative orientation and a disposable cassetteassembly including a cassette housing element, a prefilled syringeincluding a needle and a needle guard element. The cassette housingelement and the needle guard element being arranged such that prior toboth the disposable cassette assembly having been inserted into thereusable driving assembly and the reusable driving assembly being in theneedle insertion operative orientation, the relative axial displacementbetween the cassette housing element and the needle guard element isprevented.

Preferably, the arrangement of the cassette housing element and theneedle guard element is such that the relative axial displacementbetween the cassette housing element and the needle guard element isprevented by first and second engagements, the first engagement beingreleased upon insertion of the disposable cassette assembly into thereusable driving assembly and the second engagement being released whenthe reusable driving assembly is in the needle insertion operativeorientation.

Still preferably, the first engagement is provided by mutual engagementof at least one first protrusion of the needle guard element with atleast one first slot of the cassette housing element and the secondengagement is provided by mutual engagement of at least one secondprotrusion of the needle guard element with at least one second slot ofthe cassette housing element.

Yet preferably, the disposable cassette has a pre-use operativeorientation, which is suitable for storage. In the pre-use operativeorientation, the needle guard element is locked to the cassette housingelement by snap fit engagement of at least one protrusion of the needleguard element in at least one slot formed in the cassette housingelement.

In accordance with a preferred embodiment of the present invention thecassette housing element is arranged such that upon the reusable drivingassembly being in the needle insertion operative orientation, resultingaxial displacement of the syringe produces outward displacement of aportion of the cassette housing element into engagement with a forwardbase element of the reusable driving assembly, thereby limiting thepenetration depth of the needle.

Preferably, the axial position of the forward base element of thereusable driving assembly is adjustable.

Further preferably, the reusable driving assembly includes a forwardinjection end and multiple mutually axially displaceable elements, theneedle is suitable for injecting an injectable liquid at an injectionsite, the disposable cassette assembly is removably insertable into thereusable driving assembly at the forward injection end and followinginsertion of the disposable cassette assembly into the reusable drivingassembly, the automatic injection device may be caused to assume aninjection site engagement operative orientation by pressing the forwardinjection end of the reusable driving assembly against the injectionsite, thereby producing mutual axial displacement of at least some ofthe multiple mutually axially displaceable elements but not producingrelative axial displacement between the needle guard element and thecassette housing element of the disposable cassette assembly.

Still preferably, following insertion of the disposable cassetteassembly into the reusable driving assembly, the automatic injectiondevice may be caused to assume an injection site engagement operativeorientation. Following assumption of the pre-needle insertion operativeorientation, the automatic injection device may be caused to assume aneedle insertion operative orientation by pressing the trigger buttonelement, thereby causing forward axial displacement of the cassettehousing element and resulting penetration of the injection site by theneedle to a penetration depth defined by engagement of the cassettehousing element with the forward base element of the reusable drivingassembly.

In accordance with a preferred embodiment of the present inventionfollowing injection the disposable cassette assembly extends partiallyoutside of the reusable driving assembly at the forward injection endand is releasably retained in the reusable driving assembly and thedisposable cassette assembly may thereafter be fully disengaged from thereusable driving assembly by axially pulling the disposable cassetteassembly out of the reusable driving assembly.

Preferably, wherein only following insertion and retention of thedisposable cassette assembly in the reusable driving assembly, theautomatic injection device may be caused to assume a needle insertionoperative orientation by pressing the trigger button element, therebycausing forward axial displacement of the cassette housing element andresulting penetration of the injection site by the needle.

Further preferably, the reusable driving assembly includes a plungerelement, a forward cover element and a rearward cover element, a springand at least one cocked orientation retaining element operative in acocked operative orientation of the reusable driving assembly forcocking the plunger element against the urging of the spring andretaining the plunger element in the cocked operative orientation.

Still preferably, the forward cover element and the rearward coverelement move towards each other in assuming the cocked operativeorientation and when in the cocked operative orientation are lockedagainst mutual axial displacement.

Yet preferably, the disposable cassette assembly includes a cassettehousing element, a prefilled syringe including a needle for injecting aninjectable liquid at an injection site and a needle guard element, andfollowing injection and removal of the needle from the injection site,assumption of the cocked operative orientation is possible thereafteronly following forward displacement of the needle guard element relativeto the needle.

In accordance with a preferred embodiment of the present invention thereusable driving assembly includes a forward injection end, a safetycatch element and a trigger button element. The automatic injectiondevice may be caused to assume a needle insertion operative orientationby pressing the trigger button element, thereby causing forward axialdisplacement of the cassette housing element and resulting penetrationof the injection site by the needle, only when all of the followingconditions are met: the reusable driving assembly is in a cockedoperative orientation, the disposable cassette assembly is inserted andretained in the reusable driving assembly, and the safety catch elementis in a disengaged operative orientation.

Preferably, the automatic injection device may be caused to assume aneedle insertion operative orientation by pressing the trigger buttonelement, thereby causing forward axial displacement of the cassettehousing element and resulting penetration of the injection site by theneedle, only when all of the following conditions are met: the reusabledriving assembly is in a cocked operative orientation, and thereafterthe disposable cassette assembly is fully inserted and retained in thereusable driving assembly, and thereafter the safety catch element is ina disengaged operative orientation.

There is even further provided in accordance with still anotherpreferred embodiment of the present invention an automatic injectiondevice including a reusable driving assembly having a needle insertionoperative orientation and having a forward base element and a disposablecassette assembly including a cassette housing element, a syringeincluding a needle and a needle guard element. The cassette housingelement being arranged such that upon the reusable driving assemblybeing in the needle insertion operative orientation, resulting axialdisplacement of the syringe produces outward displacement of a portionof the cassette housing element into engagement with the forward baseelement of the reusable driving assembly, thereby limiting thepenetration depth of the needle.

Preferably, the axial position of the forward base element of thereusable driving assembly is adjustable.

Further preferably, the reusable driving assembly includes a forwardinjection end and multiple mutually axially displaceable elements, theneedle is suitable for injecting an injectable liquid at an injectionsite, the disposable cassette assembly is removably insertable into thereusable driving assembly at the forward injection end and followinginsertion of the disposable cassette assembly into the reusable drivingassembly, the automatic injection device may be caused to assume aninjection site engagement operative orientation by pressing the forwardinjection end of the reusable driving assembly against the injectionsite, thereby producing mutual axial displacement of at least some ofthe multiple mutually axially displaceable elements but not producingrelative axial displacement between the needle guard element and thecassette housing element of the disposable cassette assembly.

Still preferably, following insertion of the disposable cassetteassembly into the reusable driving assembly, the automatic injectiondevice may be caused to assume an injection site engagement operativeorientation. Following assumption of the pre-needle insertion operativeorientation, the automatic injection device may be caused to assume aneedle insertion operative orientation by pressing the trigger buttonelement, thereby causing forward axial displacement of the cassettehousing element and resulting penetration of the injection site by theneedle to a penetration depth defined by engagement of the cassettehousing element with the forward base element of the reusable drivingassembly.

In accordance with a preferred embodiment of the present inventionfollowing injection the disposable cassette assembly extends partiallyoutside of the reusable driving assembly at the forward injection endand is releasably retained in the reusable driving assembly and thedisposable cassette assembly may thereafter be fully disengaged from thereusable driving assembly by axially pulling the disposable cassetteassembly out of the reusable driving assembly.

Preferably, only following insertion and retention of the disposablecassette assembly in the reusable driving assembly, the automaticinjection device may be caused to assume a needle insertion operativeorientation by pressing the trigger button element, thereby causingforward axial displacement of the cassette housing element and resultingpenetration of the injection site by the needle.

Further preferably, the reusable driving assembly includes a plungerelement, a forward cover element and a rearward cover element, a springand at least one cocked orientation retaining element operative in acocked operative orientation of the reusable driving assembly forcocking the plunger element against the urging of the spring andretaining the plunger element in the cocked operative orientation.

In accordance with a preferred embodiment of the present invention theforward cover element and the rearward cover element move towards eachother in assuming the cocked operative orientation and when in thecocked operative orientation are locked against mutual axialdisplacement.

Preferably, the disposable cassette assembly includes a cassette housingelement, a prefilled syringe including a needle for injecting aninjectable liquid at an injection site and a needle guard element andfollowing injection and removal of the needle from the injection site,assumption of the cocked operative orientation is possible thereafteronly following forward displacement of the needle guard element relativeto the needle.

Further preferably, the reusable driving assembly includes a forwardinjection end, a safety catch element and a trigger button element, theautomatic injection device may be caused to assume a needle insertionoperative orientation by pressing the trigger button element, therebycausing forward axial displacement of the cassette housing element andresulting penetration of the injection site by the needle, only when allof the following conditions are met: the reusable driving assembly is ina cocked operative orientation, the disposable cassette assembly isinserted and retained in the reusable driving assembly, and the safetycatch element is in a disengaged operative orientation.

Still preferably, the automatic injection device may be caused to assumea needle insertion operative orientation by pressing the trigger buttonelement, thereby causing forward axial displacement of the cassettehousing element and resulting penetration of the injection site by theneedle, only when all of the following conditions are met: the reusabledriving assembly is in a cocked operative orientation and thereafter thedisposable cassette assembly is fully inserted and retained in thereusable driving assembly, and thereafter the safety catch element is ina disengaged operative orientation.

There is even further provided in accordance with still anotherpreferred embodiment of the present invention an automatic injectiondevice including a reusable driving assembly having a forward injectionend and multiple mutually axially displaceable elements and a disposablecassette assembly including a cassette housing element, a prefilledsyringe including a needle for injecting an injectable liquid at aninjection site and a needle guard element. The disposable cassetteassembly is removably insertable into the reusable driving assembly atthe forward injection end, following insertion of the disposablecassette assembly into the reusable driving assembly, the automaticinjection device may be caused to assume an injection site engagementoperative orientation by pressing the forward injection end of thereusable driving assembly against the injection site, thereby producingmutual axial displacement of at least some of the multiple mutuallyaxially displaceable elements but not producing relative axialdisplacement between the needle guard element and the cassette housingelement of the disposable cassette assembly.

Preferably, following insertion of the disposable cassette assembly intothe reusable driving assembly, the automatic injection device may becaused to assume an injection site engagement operative orientation.Following assumption of the pre-needle insertion operative orientation,the automatic injection device may be caused to assume a needleinsertion operative orientation by pressing the trigger button element,thereby causing forward axial displacement of the cassette housingelement and resulting penetration of the injection site by the needle toa penetration depth defined by engagement of the cassette housingelement with the forward base element of the reusable driving assembly.

Further preferably, following injection the disposable cassette assemblyextends partially outside of the reusable driving assembly at theforward injection end and is releasably retained in the reusable drivingassembly and the disposable cassette assembly may thereafter be fullydisengaged from the reusable driving assembly by axially pulling thedisposable cassette assembly out of the reusable driving assembly.

Still preferably, only following insertion and retention of thedisposable cassette assembly in the reusable driving assembly, theautomatic injection device may be caused to assume a needle insertionoperative orientation by pressing the trigger button element, therebycausing forward axial displacement of the cassette housing element andresulting penetration of the injection site by the needle.

In accordance with a preferred embodiment of the present invention thereusable driving assembly includes a plunger element, a forward coverelement and a rearward cover element, a spring and at least one cockedorientation retaining element operative in a cocked operativeorientation of the reusable driving assembly for cocking the plungerelement against the urging of the spring and retaining the plungerelement in the cocked operative orientation.

Preferably, the forward cover element and the rearward cover elementmove towards each other in assuming the cocked operative orientation andwhen in the cocked operative orientation are locked against mutual axialdisplacement.

Further preferably, the disposable cassette assembly includes a cassettehousing element, a prefilled syringe including a needle for injecting aninjectable liquid at an injection site and a needle guard element, andfollowing injection and removal of the needle from the injection site,assumption of the cocked operative orientation is possible thereafteronly following forward displacement of the needle guard element relativeto the needle.

In accordance with a preferred embodiment of the present invention thereusable driving assembly includes a forward injection end, a safetycatch element and a trigger button element. The automatic injectiondevice may be caused to assume a needle insertion operative orientationby pressing the trigger button element, thereby causing forward axialdisplacement of the cassette housing element and resulting penetrationof the injection site by the needle, only when all of the followingconditions are met: the reusable driving assembly is in a cockedoperative orientation, the disposable cassette assembly is inserted andretained in the reusable driving assembly, and the safety catch elementis in a disengaged operative orientation.

Preferably, the automatic injection device may be caused to assume aneedle insertion operative orientation by pressing the trigger buttonelement, thereby causing forward axial displacement of the cassettehousing element and resulting penetration of the injection site by theneedle, only when all of the following conditions are met: the reusabledriving assembly is in a cocked operative orientation and thereafter thedisposable cassette assembly is fully inserted and retained in thereusable driving assembly, and thereafter the safety catch element is ina disengaged operative orientation.

There is also provided in accordance with yet another preferredembodiment of the present invention an automatic injection deviceincluding a reusable driving assembly having a forward injection end, aforward base element, and a trigger button element and a disposablecassette assembly including a cassette housing element, a syringeincluding a needle for injecting an injectable liquid at an injectionsite and a needle guard element. The disposable cassette assembly isremovably insertable into the reusable driving assembly at the forwardinjection end. Following insertion of the disposable cassette assemblyinto the reusable driving assembly, the automatic injection device maybe caused to assume an injection site engagement operative orientationand following assumption of the pre-needle insertion operativeorientation, the automatic injection device may be caused to assume aneedle insertion operative orientation by pressing the trigger buttonelement, thereby causing forward axial displacement of the cassettehousing element and resulting penetration of the injection site by theneedle to a penetration depth defined by engagement of the cassettehousing element with the forward base element of the reusable drivingassembly.

Preferably, following injection the disposable cassette assembly extendspartially outside of the reusable driving assembly at the forwardinjection end and is releasably retained in the reusable drivingassembly and the disposable cassette assembly may thereafter be fullydisengaged from the reusable driving assembly by axially pulling thedisposable cassette assembly out of the reusable driving assembly.

Further preferably, only following insertion and retention of thedisposable cassette assembly in the reusable driving assembly, theautomatic injection device may be caused to assume a needle insertionoperative orientation by pressing the trigger button element, therebycausing forward axial displacement of the cassette housing element andresulting penetration of the injection site by the needle.

In accordance with a preferred embodiment of the present invention thereusable driving assembly includes a plunger element, a forward coverelement and a rearward cover element, a spring and at least one cockedorientation retaining element operative in a cocked operativeorientation of the reusable driving assembly for cocking the plungerelement against the urging of the spring and retaining the plungerelement in the cocked operative orientation.

Preferably, the forward cover element and the rearward cover elementmove towards each other in assuming the cocked operative orientation andwhen in the cocked operative orientation are locked against mutual axialdisplacement.

Further preferably, the disposable cassette assembly includes a cassettehousing element, a prefilled syringe including a needle for injecting aninjectable liquid at an injection site and a needle guard element, andfollowing injection and removal of the needle from the injection site,assumption of the cocked operative orientation is possible thereafteronly following forward displacement of the needle guard element relativeto the needle.

Still preferably, the reusable driving assembly includes a forwardinjection end, a safety catch element and a trigger button element andthe automatic injection device may be caused to assume a needleinsertion operative orientation by pressing the trigger button element,thereby causing forward axial displacement of the cassette housingelement and resulting penetration of the injection site by the needle,only when all of the following conditions are met: the reusable drivingassembly is in a cocked operative orientation, the disposable cassetteassembly is inserted and retained in the reusable driving assembly, andthe safety catch element is in a disengaged operative orientation.

Yet further preferably, the automatic injection device may be caused toassume a needle insertion operative orientation by pressing the triggerbutton element, thereby causing forward axial displacement of thecassette housing element and resulting penetration of the injection siteby the needle, only when all of the following conditions are met: thereusable driving assembly is in a cocked operative orientation andthereafter the disposable cassette assembly is fully inserted andretained in the reusable driving assembly, and thereafter the safetycatch element is in a disengaged operative orientation.

There is still further provided in accordance with a further preferredembodiment of the present invention an automatic injection deviceincluding a reusable driving assembly having a forward injection end,and a disposable cassette assembly. The disposable cassette assembly isremovably insertable into the reusable driving assembly at the forwardinjection end, following injection, the disposable cassette assemblyextends partially outside of the reusable driving assembly at theforward injection end and is releasably retained in the reusable drivingassembly and the disposable cassette assembly may thereafter be fullydisengaged from the reusable driving assembly by axially pulling thedisposable cassette assembly out of the reusable driving assembly.

Preferably, only following insertion and retention of the disposablecassette assembly in the reusable driving assembly, the automaticinjection device may be caused to assume a needle insertion operativeorientation by pressing the trigger button element, thereby causingforward axial displacement of the cassette housing element and resultingpenetration of the injection site by the needle.

Further preferably, the reusable driving assembly includes a plungerelement, a forward cover element and a rearward cover element, a springand at least one cocked orientation retaining element operative in acocked operative orientation of the reusable driving assembly forcocking the plunger element against the urging of the spring andretaining the plunger element in the cocked operative orientation.

There is yet further provided in accordance with a still furtherpreferred embodiment of the present invention an automatic injectiondevice including a reusable driving assembly having a forward injectionend and a trigger button element and a disposable cassette assembly. Thedisposable cassette assembly is removably insertable and retainable intothe reusable driving assembly at the forward injection end and onlyfollowing insertion and retention of the disposable cassette assembly inthe reusable driving assembly, the automatic injection device may becaused to assume a needle insertion operative orientation by pressingthe trigger button element, thereby causing forward axial displacementof the cassette housing element and resulting penetration of theinjection site by the needle.

There is still further provided in accordance with a yet furtherpreferred embodiment of the present invention an automatic injectiondevice including a reusable driving assembly including a plungerelement, a forward cover element and a rearward cover element, a springand at least one cocked orientation retaining element operative in acocked operative orientation of the reusable driving assembly forcocking the plunger element against the urging of the spring andretaining the plunger element in the cocked operative orientation and adisposable cassette assembly which is removably insertable in thereusable driving assembly and includes a needle.

There is yet further provided in accordance with a still furtherpreferred embodiment of the present invention an automatic injectiondevice including a reusable driving assembly including a plungerelement, a rearward cover element, a forward cover element, a springwhich applies an axial force to said rearward cover element and theforward cover element and at least one cocked orientation retainingelement operative in a cocked operative orientation of the reusabledriving assembly for cocking the plunger element against the urging ofthe spring and retaining the plunger element in the cocked operativeorientation and a safety-catch element having engaged and disengagedoperative orientations and a disposable cassette assembly which isremovably insertable in the reusable driving assembly only when thereusable driving assembly is in the cocked operative orientation and thesafety catch element is in said engaged operative orientation.

There is still further provided in accordance with a yet furtherpreferred embodiment of the present invention an automatic injectiondevice including a reusable driving assembly having a forward injectionend, a safety catch element and a trigger button element and adisposable cassette assembly. The disposable cassette assembly isremovably insertable and retainable into the reusable driving assemblyat the forward injection end and the automatic injection device may becaused to assume a needle insertion operative orientation by pressingthe trigger button element, thereby causing forward axial displacementof the cassette housing element and resulting penetration of theinjection site by the needle, only when all of the following conditionsare met: the reusable driving assembly is in a cocked operativeorientation, the disposable cassette assembly is inserted and retainedin the reusable driving assembly, and the safety catch element is in adisengaged operative orientation.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description, taken in conjunction with thedrawings in which:

FIG. 1 is a simplified exploded view illustration of an automaticinjection device constructed and operative in accordance with anembodiment of the present invention;

FIG. 2 is a simplified pictorial illustration of a cassette housingelement which forms part of the automatic injection device of FIG. 1;

FIG. 3 is a front view simplified planar illustration of the cassettehousing element of FIG. 2;

FIGS. 4A & 4B are two different side view simplified planarillustrations of the cassette housing element of FIG. 2;

FIGS. 4C & 4D are sectional illustrations of the cassette housingelement taken along respective section lines C-C and D-D in FIG. 3;

FIG. 5 is a simplified pictorial illustration of a needle guard elementwhich forms part of the automatic injection device of FIG. 1;

FIG. 6 is a front view simplified planar illustration of the needleguard element of FIG. 5;

FIGS. 7A & 7B are two different side view simplified planarillustrations of the needle guard element of FIG. 5;

FIGS. 7C-7E are sectional illustrations of the needle guard elementtaken along respective section lines C-C; D-D and E-E in FIG. 6;

FIG. 8 is a simplified pictorial illustration of a needle shield removerelement which forms part of the automatic injection device of FIG. 1;

FIG. 9 is a front view simplified planar illustration of the needleshield remover element of FIG. 8;

FIGS. 10A & 10B are sectional illustrations of the needle shield removerelement taken along respective section lines A-A and B-B in FIG. 9;

FIG. 11 is a simplified assembled view illustration of the disposablecassette assembly of the automatic injection device of FIG. 1 in apre-use operative orientation:

FIGS. 12A & 12B are simplified respective side and top view planarillustrations of the disposable cassette assembly of FIG. 11;

FIGS. 13A, 13B and 13C are sectional illustrations of the disposablecassette assembly taken along respective section lines A-A, B-B and C-Cin FIGS. 12A and 12B;

FIGS. 14A & 14B are simplified pictorial illustrations of a forward baseelement of the automatic injection device of FIG. 1;

FIGS. 15A, 15B and 15C are respective side, top and front views of theforward base of FIGS. 14A & 14B;

FIGS. 16A & 16B are sectional illustrations of the forward base of FIGS.14A & 14B taken along respective section lines A-A and B-B in FIGS. 15Aand 15B;

FIGS. 17A & 17B are simplified pictorial illustrations of needlepenetration depth selector of the automatic injection device of FIG. 1:

FIG. 18 is simplified side view of the needle penetration depth selectorof FIGS. 17A & 17B;

FIGS. 19A & 19B are sectional illustrations of the needle penetrationdepth selector taken along respective section lines A-A in FIG. 18 andB-B in FIG. 17A;

FIGS. 20A & 20B are simplified pictorial illustrations of a cockedorientation retaining element of the automatic injection device of FIG.1;

FIGS. 21A, 21B, 21C and 21D, which are simplified respective top, side,back and front views of the cocked orientation retaining element ofFIGS. 20A & 20B;

FIG. 22 is a sectional illustration of the cocked orientation retainingelement taken along section line A-A in FIG. 21A;

FIGS. 23A & 23B are simplified pictorial illustrations of forward coverelement of the automatic injection device of FIG. 1;

FIGS. 24A, 24B, 24C and 24D are respective simplified side, top, frontand back views of forward cover element of FIGS. 23A & 23B;

FIGS. 25A & 25B are simplified sectional illustrations of the forwardcover element taken along respective section lines A-A and B-B in FIGS.24A and 24B;

FIGS. 26A & 26B are simplified pictorial illustrations of a needle guarddeploying element of the automatic injection device of FIG. 1;

FIGS. 27A, 27B, 27C and 27D are simplified respective side, top, frontand back views of the needle guard deploying element of FIGS. 26A & 26B;

FIGS. 28A & 28B are simplified sectional illustrations of the needleguard deploying element taken along respective section lines A-A and B-Bin FIGS. 27A & 27B;

FIGS. 29A & 29B are simplified pictorial illustrations of a plungerelement of the automatic injection device of FIG. 1;

FIGS. 30A, 30B, 30C and 30D are simplified respective top, side, frontand back views of the plunger element of FIGS. 29A & 29B:

FIGS. 31A & 31B are simplified sectional illustrations of the plungerelement taken along respective section lines A-A and B-B in FIGS. 30A &30B;

FIGS. 32A & 32B are simplified pictorial illustrations of a rear coverelement of the automatic injection device of FIG. 1;

FIGS. 33A, 33B, 33C and 33D are simplified respective side, top, frontand back views of the rear cover element of FIGS. 32A & 32B;

FIGS. 34A & 34B are simplified sectional illustrations of the rear coverelement taken along respective section lines A-A and B-B in FIGS. 33A &33B;

FIGS. 35A & 35B are simplified pictorial illustrations of a triggerbutton element of the automatic injection device of FIG. 1:

FIGS. 36A, 36B and 36C are simplified respective side, top and frontviews of the trigger button element of FIGS. 35A & 35B;

FIG. 37 is a simplified sectional illustration of the trigger buttontaken along section line A-A in FIG. 36B;

FIGS. 38A & 38B are simplified pictorial illustrations of a safety-catchelement of the automatic injection device of FIG. 1;

FIGS. 39A, 39B and 39C, which are simplified respective side, front andback views of the safety-catch element of FIGS. 38A & 38B:

FIG. 40 is a simplified sectional illustration of the safety-catchelement taken along section line A-A in FIG. 39A;

FIGS. 41A & 41B are simplified pictorial illustrations of a rear baseelement of the automatic injection device of FIG. 1;

FIGS. 42A, 42B, 42C and 42D are simplified respective side, top, frontand back views of the rear base element of FIGS. 41A & 41B;

FIGS. 43A & 43B are simplified sectional illustrations of the rear baseelement taken along respective section lines A-A and B-B in FIGS. 42A &42B;

FIG. 44 is a simplified assembled view illustration of the reusabledriving assembly of the automatic injection device of FIG. 1 in astorage operative orientation;

FIGS. 45A & 45B are simplified respective side and top views of theassembled view illustration of the reusable driving assembly of FIG. 44;

FIGS. 46A, 46B, 46C, 46D, 46E and 46F, which are simplified sectionalillustrations taken along respective section lines A-A, B-B, C-C, D-D,E-E and F-F in FIGS. 45A and 45B.

FIG. 47 is a simplified side view illustration in the sense of FIGS.44-46C of an assembly including the forward cover element of FIGS.23A-25B, the needle penetration depth selector of FIGS. 17A-19B and theforward base element of FIGS. 14A-16B;

FIGS. 48A, 48B and 48C are simplified cross-sectional illustrationstaken along respective lines A-A, B-B and C-C in FIG. 47 and FIG. 48D isa pictorial cross-sectional illustration taken along lines C-C in FIG.47;

FIGS. 49A & 49B are simplified respective side and top views, in thesense of FIGS. 44-46D, of an assembly of needle guard deploying spring,needle guard deploying element of FIGS. 26A-28B and rear base element ofFIGS. 41A-43B:

FIGS. 50A & 50B are simplified respective sectional illustrations takenalong lines A-A and B-B in FIG. 49A;

FIG. 51 is a simplified side view, in the sense of FIGS. 44-46D, of anassembly of rear cover element of FIGS. 32A-34B, trigger button elementof FIGS. 35A-37 and safety catch element of FIGS. 38A-40;

FIGS. 52A & 52B are simplified respective planar and pictorialcross-sectional view both taken along lines A-A in FIG. 51;

FIG. 53 is a simplified cross-sectional view taken along lines B-B inFIG. 51;

FIGS. 54A & 54B are simplified respective side and bottom viewillustrations of an assembly which includes the assembly of FIGS.49A-50B mounted within the assembly of FIGS. 51-53;

FIG. 55 is a simplified sectional illustration taken along lines A-A inFIG. 54B;

FIG. 56 is a simplified assembled view illustration of the reusabledriving assembly of the automatic injection device of FIG. 1 in acocking operative orientation;

FIGS. 57A & 57B are simplified respective side and top views of thereusable driving assembly of FIG. 56;

FIGS. 58A, 58B, 58C and 58D are simplified sectional illustrations takenalong respective section lines A-A, B-B, C-C and D-D in FIGS. 57A and57B;

FIG. 59 is a simplified assembled view illustration of the reusabledriving assembly of the automatic injection device of FIG. 1 in a cockedoperative orientation;

FIGS. 60A & 60B are simplified respective side and top views of thereusable driving assembly of FIG. 59 and of disposable cassette assemblyarranged coaxially therewith ready for insertion thereinto;

FIGS. 61A, 61B, 61C and 61D are simplified sectional illustrations takenalong respective section lines A-A, B-B. C-C and D-D in FIGS. 60A and60B;

FIG. 62 is a simplified assembled view illustration of the reusabledriving assembly of the automatic injection device of FIG. 1 in apre-injection operative orientation, having the disposable cassetteassembly fully inserted therein and the needle shield remover and theneedle shield removed from the disposable cassette assembly;

FIGS. 63A & 63B are simplified respective side and top views of thereusable driving assembly of FIG. 62;

FIGS. 64A, 64B and 64C are simplified sectional illustrations takenalong respective section lines A-A, B-B and C-C in FIGS. 63A and 63B:

FIG. 65 is a simplified assembled view illustration of the reusabledriving assembly of the automatic injection device of FIG. 1 in aninjection site engagement operative orientation;

FIGS. 66A & 66B are simplified respective side and top views of thereusable driving assembly of FIG. 65;

FIGS. 67A, 67B and 67C are simplified sectional illustrations takenalong respective section lines A-A, B-B and C-C in FIGS. 66A and 66B;

FIG. 68 is a simplified assembled view illustration of the reusabledriving assembly of the automatic injection device of FIG. 1 in a needleinsertion operative orientation;

FIGS. 69A & 69B are simplified respective side and top views of thereusable driving assembly of FIG. 68;

FIGS. 70A, 70B and 70C are simplified sectional illustrations takenalong respective section lines A-A, B-B and C-C in FIGS. 69A & 69B;

FIG. 71 is a simplified assembled view illustration of the reusabledriving assembly of the automatic injection device of FIG. 1 in anend-of-injection operative orientation;

FIGS. 72A & 72B are simplified respective side and top views of thereusable driving assembly of FIG. 71;

FIGS. 73A, 73B and 73C are simplified sectional illustrations takenalong respective section lines A-A, B-B and C-C in FIGS. 72A & 72B;

FIG. 74 is a simplified assembled view illustration of the reusabledriving assembly of the automatic injection device of FIG. 1 in apost-injection operative orientation;

FIGS. 75A & 75B are simplified respective side and top views of thereusable driving assembly of FIG. 74; and

FIGS. 76A, 76B and 76C are simplified sectional illustrations takenalong respective section lines A-A, B-B and C-C in FIGS. 75A & 75B.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Reference is now made to FIG. 1, which illustrates elements of anautomatic injection device constructed and operative in accordance witha preferred embodiment of the present invention.

As seen in FIG. 1, the automatic injection device preferably comprises adisposable cassette assembly 100, which is described hereinbelow ingreater detail with reference to FIGS. 11-13C, and a reusable drivingassembly 110, which is described hereinbelow in greater detail withreference to FIGS. 44-46C. The disposable cassette assembly 100comprises a cassette housing element 120 in which is seated a needleguard element 122 and a syringe 124 including a piston 125, a flange 126and a hypodermic needle 128, which is preferably covered by a needleshield 130. The syringe 124 is preferably pre-filled with liquid 131.Syringe 124 may be any suitable conventional syringe, such as acommercially available syringe sold under the catalog designationBD-Hypak™.

A needle shield remover 140 preferably forms part of the disposablecassette assembly 100. Alternatively it could be provided as a reusablepart which is mounted onto the disposable cassette assembly 100 by theend user.

The reusable driving assembly 110 preferably comprises a forward baseelement 150, onto a front end of is preferably screwed a needlepenetration depth selector 152, a pair of orientation retaining elements154 and a pair of cocking springs 156, each which is mounted at a backend thereof onto one of the cocked orientation retaining elements 154. Aforward cover element 158 generally encloses the forward base element150 and the needle penetration depth selector 152.

A needle guard deploying spring 160 urges an engagement element, here aneedle guard deploying element 162, in a forward direction indicatedgenerally by an arrow 164 and a main spring 166 urges a plunger element168 in the forward direction indicated generally by arrow 164.

A rear cover element 170 generally encloses a rear base element 172,which in turn, generally encloses elements 160, 162, 166 and 168. Atrigger button element 174 cooperates with rear cover element 170. Rearcover element 170 also generally encloses a safety-catch element 176 andan injection site engagement sensing spring 178.

Rear base element 172 provides a rear spring seats for the main spring166 and for injection site engagement sensing spring 178 and providesfront spring seats for cocking springs 156.

Reference is now made to FIGS. 2, 3, 4A, 4B. 4C & 4D which illustratecassette housing element 120. As seen in FIGS. 2-4B, the cassettehousing element 120 preferably is an integrally formed element,preferably injection molded of plastic and preferably has a generallycylindrical configuration including a generally tubular portion 200,which defines backward-facing generally symmetric edges 202 andgenerally symmetric side-facing windows 204. Side-facing windows 204 maybe obviated, if cassette housing element 120 is formed of a transparentmaterial.

Cassette housing element 120 is preferably side-to-side symmetric abouta longitudinal axis 206 and defines a generally round internal surfacewhich slidingly guides syringe 124 (FIG. 1).

Cassette housing element 120 is preferably formed with a pair ofgenerally symmetric top and bottom longitudinal extensions 208 and 210,each having a generally rectangular cross-section. Top and bottomlongitudinal extensions 208 and 210 preferably terminate in respectiverearward facing flat protrusions 212 and 214.

Finger portions 216 and 218 extend forwardly from respective top andbottom longitudinal extensions 208 and 210 and parallel to longitudinalaxis 206, each of finger portions preferably terminating in an inwardfacing protrusion 220 and a pair of generally symmetric side-to-sidefacing protrusions 222.

Top longitudinal extension 208 is preferably formed with a pair ofmutually spaced longitudinal ribs 230 and 232 on a first side thereofand a pair of mutually spaced longitudinal ribs 234 and 236 on a secondside thereof.

Bottom longitudinal extension 210 is preferably formed with a pair ofmutually spaced longitudinal ribs 240 and 242 on a first side thereofand a pair of mutually spaced longitudinal ribs 244 and 246 on a secondside thereof.

A track 250 is defined by mutually spaced longitudinal ribs 230 and 232and a track 252 is defined by mutually spaced longitudinal ribs 234 and236.

A track 254 is defined by mutually spaced longitudinal ribs 240 and 242and a track 256 is defined by mutually spaced longitudinal ribs 244 and246.

Forward slots 260 and 262 and rearward slots 264 and 266 are definedalong respective tracks 250, 252, 254 and 256. Forward slots 260 and 262each include a forward facing edge 268 and a rearward facing edge 270.Rearward slots 264 and 266 each include a forward facing edge 278 and arearward facing edge 280.

Reference is now made to FIGS. 5, 6, 7A, 7B, 7C, 7D & 7E whichillustrate needle guard element 122 (FIG. 1). As seen in FIGS. 5-7E, theneedle guard element 122 preferably is an integrally formed element,preferably injection molded of plastic and preferably has a generallycylindrical configuration arranged about a longitudinal axis 300,including a generally tubular portion 301 and having a forward facinginjection site engaging surface 302, preferably including a pair ofmutually concentric ribbed circumferential forward facing injection siterings 304 and 306.

Needle guard element 122 includes a pair of top and bottom mounting arms308 and 310 extending rearwardly from tubular portion 301 and havingrespective rearward facing edges 312 and 314. Each of mounting arms 308and 310 is formed with a slot 316 having a rearward-facing taperedsurface 318. Each of mounting arms 308 and 310 is additionally formedwith a pair of side-to-side symmetric notches 320.

Slightly forwardly of each of respective rearward facing edges 312 and314, there are provided a pair of symmetric protrusions 322, each havinga forward-facing surface 324.

Mounting arm 308 is formed with respective forward and rearwardresilient finger portions 326 and 328. Mounting arm 310 is formed withrespective forward and rearward resilient finger portions 336 and 338.Finger portion 326 and 336 each include an outwardly-facing protrusion340, a forward-facing tapered surface 342, a rearward-facing taperedsurface 344 and a rearward facing edge 346. Finger portions 328 and 338each include an outwardly-facing protrusion 350, a forward-facingtapered surface 352, a rearward-facing tapered surface 354 and arearward facing edge 356.

Reference is now made to FIGS. 8, 9, 10A & 10B, which illustrate needleshield remover 140. As seen in FIGS. 8-10B, the needle shield remover140 preferably is an integrally formed element preferably injectionmolded of plastic and has a generally tubular portion 360, arrangedabout a longitudinal axis 362 and having an external user fingerengagement surface 364. Needle shield remover 140, which when assembledtogether with needle guard element 122, cassette housing element 120 andsyringe 124 defines the disposable cassette assembly 100, such thatlongitudinal axes 206, 300 and 362 are mutually coaxial.

Needle shield remover 140 includes a pair of symmetrical arms 370 whichextend rearwardly of external user finger engagement surface 364 and areeach formed with an outwardly-facing rib 372, having backwardly-facingtapered surfaces 374. Each of symmetrical arms 370 is additionallyformed adjacent a rearwardly facing end surface 376 thereof with aninternally facing protrusion 378, having a forward facing surface 380.

Reference is now made to FIG. 11, which is a simplified assembled viewillustration of the disposable cassette assembly 100 of the automaticinjection device of FIG. 1 in a pre-use operative orientation arrangedalong a longitudinal axis 390, to FIGS. 12A and 12B, which aresimplified respective side and top view planar illustrations thereof inthe sense of FIG. 11 and to FIGS. 13A, 13B and 13C, which are sectionalillustrations taken along respective section lines A-A, B-B and C-C inFIGS. 12A and 12B.

As seen in FIGS. 11-13C, in a pre-use operative orientation of thedisposable cassette which is suitable for storage, the needle guardelement 122 is joined and locked to the cassette housing element 120 bysnap fit engagement of outwardly-facing protrusions 340 and protrusions350 of needle guard element 122 in corresponding forward slots 260 & 262and rearward slots 264 & 266, respectively formed in the cassettehousing element 120.

Rearward facing edge 356 of outwardly-facing protrusion 350 of fingerportions 328 and 338 are located against corresponding rearward-facingedges 278 of rearward slots 264 and 266 respectively, thereby limitingforward movement of the syringe 124. Backward movement of the syringe124 is limited by engagement of the flange 126 with forward-facingsurfaces 324 of internally facing symmetric protrusions 322 of mountingarms 308 and 310 of the needle guard element 122. Outward spreading ofmounting arms 308 and 310 is limited by generally symmetric top andbottom longitudinal extensions 208 and 210 of the cassette housingelement 120 and thus mounting arms 308 and 310 cannot disengage fromflange 126.

Syringe 124 is thus retained in a retracted operative orientation byengagement of flange 126 thereof between backward-facing generallysymmetric edges 202 formed in cassette housing element 120 andforward-facing surface 324 of needle guard element 122 (FIGS. 2-7C).

Inward facing protrusions 220 of cassette housing element 120 arelocated in slots 316 of needle guard element 122.

It is noted that outwardly-facing protrusions 340 of needle guardelement 122, which are located within respective forward slots 260 &262, are also each surrounded on two sides thereof between respectivepairs of longitudinal ribs 230 & 232 and 244 & 246.

It is also noted that outwardly-facing protrusions 350 of needle guardelement 122, which are located within respective rearward slots 264 &266, are also each surrounded on two sides thereof between respectivepairs of longitudinal ribs 234 & 236 and 240 & 242.

The foregoing arrangement of ribs prevents user access tooutwardly-facing protrusions 340 and 350 and undesired disengagementthereof from respective forward slots 260 & 262 and rearward slots 264and 266. As a result, undesired axial movement of the syringe 124 is notpossible in this pre-use operative orientation and therefore thehypodermic needle 128 of syringe 124 is safely locked in the disposablecassette assembly 100 and accidental needle stick cannot occur.Furthermore, in the pre-use operative orientation, the hypodermic needle128 of the syringe 124 is generally hidden from view within thedisposable cassette assembly 100, thus reducing user needle phobia.

As also seen in FIGS. 11-13C, in a pre-use operative orientation of thedisposable cassette which is suitable for storage, needle shield remover140 is preferably attached to the disposable cassette assembly 100 withinternally facing protrusions 378 of symmetrical arms 370 of needleshield remover 140 being engaged with needle guard element 122 ofsyringe 124. Arms 370 together with outwardly-facing ribs 372 of needleshield remover 140 support the needle shield remover 140 within theneedle guard element 122.

The contents of the syringe 124 can be easily seen through theside-facing windows 204 formed in the cassette housing element 120,thereby allowing visual inspection of the contents of the syringe priorto use.

It is appreciated that the syringe 124 may be supplied with aconventional plunger rod (not shown) to facilitate air-purging, drugtitration and drug reconstitution or pumping from a vial/ampoule (notshown). The syringe may be supplied either pre-filled with aready-to-inject drug, or it may be supplied empty for filling prior touse. It is also acknowledged that the syringe 124 can be inserted intothe disposable cassette assembly 100 by a user or a pharmacist.

Reference is now made to FIGS. 14A and 14B, which are simplifiedpictorial illustrations of a forward base element 150, forming part ofthe reusable driving assembly 110 of the automatic injection device ofFIG. 1; to FIGS. 15A, 15B and 15C, which are respective side, top andfront views thereof in the sense of FIG. 14A; and to FIGS. 16A and 16B,which are sectional illustrations taken along respective section linesA-A and B-B in FIGS. 15A and 15B.

As seen in FIGS. 14A-16B, the forward base element 150 preferably is anintegrally formed element, preferably injection molded of plastic and isarranged along a longitudinal axis 400 and generally has side-to-sidesymmetry with respect to axis 400.

Forward base element 150 preferably includes a generally forward-facingtubular portion 402, which includes two pairs of outwardly extendingprotrusions respectively designated by reference numerals 404 and 406,wherein protrusions 404 are located slightly rearwardly of protrusions406 with respect to longitudinal axis 400.

Forward base element 150 preferably includes a main portion 410 having ageneral rectangular cross section including top and bottom walls 412 and414 and side walls 416 and 418. Side walls 416 and 418 are formed withgenerally symmetric forward slots 426 and 428 respectively and generallysymmetric rearward slots 436 and 438 respectively. Forward base element150 has a rearwardmost edge 440.

Side walls 416 and 418 are also formed with respective partiallycircular outer facing ribs 446 and 448 and with respective pairs offorward corner protrusions, 456 and 458. Side walls 416 and 418 are alsopreferably formed with rearward-facing cut outs 466 and 468respectively. Top and bottom walls 412 and 414 are preferably formedwith rearward-facing cut outs 476 and 478 respectively.

Preferably, respective forward facing edges of each of top and bottomwalls 412 and 414 are formed as forwardly and inwardly tapered surfaces486 and 488.

As best seen in FIG. 14A and detail C of FIG. 15C, at a forward-facingtubular portion 402 there is preferably formed an end wall 490 and thereare preferably formed a pair of generally rectangular slots 492, eachhaving a generally T-shaped cross section. End wall 490 is preferablyformed with a pair of cut outs 494 and 496.

Main portion 410 is preferably formed with a pair of internal elongaterecesses 498, which together define a slidable track adjacent top wall412 and with a pair of internal elongate recesses 499 which togetherdefine a slidable track adjacent bottom wall 414.

Main portion 410 is also preferably formed with a pair of internalelongate recesses 500, which together define a slidable track adjacentside wall 416 and with a pair of internal elongate recesses 501 whichtogether define a slidable track adjacent side wall 418. It isappreciated that the tracks defined by recesses 498 and 499 lie inplanes which are generally perpendicular to the tracks defined byrecesses 500 and 501.

A pair of internally-facing ribs 510 and 512 are provided on side wall416 and a pair of internally-facing ribs 520 and 522 are provided onside wall 418, internally-facing corresponding ribs 510 and 512. Each ofribs 510, 512, 520 and 522 is preferably provided with a taperedforward-facing edge 524 and a tapered rearward-facing edge 526.

Side walls 416 and 418 are each additionally provided with an internallyfacing rib 530, having a tapered forwardly-facing edge 532.

Reference is now made to FIGS. 17A and 17B, which are simplifiedpictorial illustrations of needle penetration depth selector 152, whichforms part of the reusable driving assembly 110 of the automaticinjection device of FIG. 1, to FIG. 18, which is a simplified side viewthereof and to FIGS. 19A and 19B, which are respective sectionalillustrations taken along section lines A-A in FIG. 18 and B-B in FIG.17A.

As seen in FIGS. 17A-19B, needle penetration depth selector 152 ispreferably an integrally formed element, preferably injection molded ofplastic, and is arranged along a longitudinal axis 550. Needlepenetration depth selector 152 preferably is formed as a generallytubular element and is preferably formed with longitudinally orientedsplines 552 extending between respective forward and rearwardcircumferential protrusions 554 and 556. Rearwardly of protrusion 556,an outer surface 557 of needle penetration depth selector 152 is formedwith four rearward-facing circumferentially distributed recesses 558.

An internal surface of needle penetration depth selector 152 ispreferably formed with a pair of helical internal threadings 560 and562. Internal threading 560 has a pair of openings 564 and 566 and aninternal disengagement preventing wall 568 adjacent opening 564.

Internal threading 562 has a pair of openings 574 and 576 and aninternal disengagement preventing wall 578 adjacent opening 574.

Reference is now made to FIGS. 20A and 20B, which are simplifiedpictorial illustrations of a cocked orientation retaining element 154,which forms part of the reusable driving assembly 110 of the automaticinjection device of FIG. 1, to FIGS. 21A, 21B, 21C and 21D, which aresimplified respective top, side, back and front views thereof, and toFIG. 22, which is a sectional illustration taken along section line A-Ain FIG. 21A;

As seen in FIGS. 20A-22, the cocked orientation retaining element 154preferably is an integrally-formed element, preferably injection moldedof plastic arranged along a longitudinal axis 600 and includes agenerally upward facing convex portion 602, in the sense of FIG. 20A,having a generally truncated frusto-conical rearward facing end portion604, and a pair of side-to-side symmetric generally flat side extensionportions 606.

As seen particularly in FIG. 20B, each of side extension portions 606includes on an underside thereof, in the sense of FIG. 20A, adjacent arearward end 607 thereof, a protrusion 608. A hook 610 having arearward-facing opening 612 extends downwardly in the sense of FIG. 20Afrom a downward-facing surface 613 of convex portion 602. Hook 610serves as a spring seat for cocking spring 156.

A pair of forward facing protrusions 614, in the sense of FIG. 20A, arelocated at a forward end of convex portion 602. Between forward facingprotrusions 614 there are provided a pair of forward-facing generallyrounded surfaces 616. An additional pair of forward-facing generallyrounded surfaces 618 are located adjacent respective protrusions 614 andon opposite sides thereof from surfaces 616. Forward-facing generallyrounded surfaces 618 define a rotational axis 620.

Reference is now made to FIGS. 23A and 23B, which are simplifiedpictorial illustrations of forward cover element 158, which forms partof the reusable driving assembly 110 of the automatic injection deviceof FIG. 1, to FIGS. 24A, 24B. 24C and 24D, which are respectivesimplified side, top, front and back views thereof, and to FIGS. 25A and25B, which are simplified sectional illustrations taken along respectivesection lines A-A and B-B in FIGS. 24A and 24B.

As seen in FIGS. 23A-25B, the forward cover element 158 preferably is anintegrally formed element, preferably injection molded of plastic, whichis arranged along a longitudinal axis 650, and has a generallyrectangular cross-section. Forward cover element 158 is preferablyformed with a pair of slightly outwardly convex side walls 652 and 654respectively and top and bottom walls 656 and 658, respectively formedwith top and bottom facing longitudinal convex portions 666 and 668.

Top and bottom walls 656 and 658 are somewhat tapered at forward facingends thereof and terminate together with forward ends of side walls 652and 654 in a forward-facing generally conical ring portion 670, having aforward-facing edge 671. Side walls 652 and 654 are preferably formedwith side-to-side symmetric rearward facing cutouts 672 and 674. Sidewalls 652 and 654 are each preferably formed with a needle penetrationdepth setting window 676, above which is provided a needle depth settingscale 678. Side walls 652 and 654 are each preferably formed with acut-out 680.

Top and bottom walls 656 and 658 preferably terminate rearwardly atrespective rearward-facing edges 682 and 684 which are rearward ofcorresponding rearward-facing edges 686 and 688 of respective side walls652 and 654. Each of rearward-facing edges 682 and 684 is provided witha pair of mutually spaced notches 690. Rearward-facing edges 682 and 684form partially circular faces 683 and 685 which form a rotational axis691.

Interior surfaces of top and bottom walls 656 and 658 are preferablyeach formed with a pair of grooves 692. An interior circumferentialsurface of forward-facing generally conical ring portion 670 defines anaxial opening 694 and is preferably formed with protrusions 696, and aforwardly and outwardly tapered facing generally circumferential taperedsurface 700.

Extending rearward from axial opening 694, internally of respective topand bottom walls 656 and 658, there are preferably provided a pair oftabs 702 and thereunder a pair of flexible snap engagement protrusions704.

Internal surfaces of side walls 652 and 654 are preferably formed withinternally-facing protrusions 706. Internal surfaces of side walls 652and 654 and top and bottom walls 656 and 658 are formed with multiplelongitudinal internally facing ribs 710.

An actuatable operative orientation indicating circumferentiallyextending line 712 is preferably defined on an outer surface of forwardcover element 158.

Reference is now made to FIGS. 26A and 26B, which are simplifiedpictorial illustrations of a needle guard deploying element 162, whichforms part of the reusable driving assembly 110 of the automaticinjection device of FIG. 1, to FIGS. 27A, 27B, 27C and 27D, which aresimplified respective side, top, front and back views thereof, and toFIGS. 28A and 28B, which are simplified sectional illustrations takenalong respective section lines A-A and B-B in FIGS. 27A and 27B.

As seen in FIGS. 26A-28B, the needle guard deploying element 162preferably is an integrally formed element, preferably injection moldedof plastic, and is arranged along a longitudinal axis 720. Element 162includes a generally tubular portion 722 at a rearward end thereof,having an outwardly extending, partially circularly circumferentialflange 724. A pair of arms 726 and 728 extend forwardly of flange 724,mutually spaced and parallel to longitudinal axis 720.

Extending rearwardly from flange 724 are a pair of flexible fingers 730,each of which has an inwardly facing, rounded protrusion 732. Extendingrearwardly and inwardly from tubular portion 722 are a pair ofprotrusions 734 preferably having outwardly and rearwardly facing,rearwardly and inwardly tapered surface 736. Extending forwardly fromflange 724 and adjacent each of arms 726 and 728 is a finger 738 havinga forwardly and outwardly tapered surface 740 facing away from therespective arm. Each of fingers 738 defines a forwardly-facing shoulder742.

Adjacent each of arms 726 and 728 and alongside a side thereof oppositeto the side adjacent to finger 738 is a finger 744. Finger 744 ispreferably formed with a forward and outward facing protrusion 746 and aforward-facing surface 748.

Formed on an outer facing surface 750 of each of arms 726 and 728 is arib 752, a major portion 754 of which extends axially forwardly from theplane of flange 724 and terminates in an angled portion 756. Also formedon an outer facing surface 750 of each of arms 726 and 728 is a rib 758,a major portion 760 of which extends axially forwardly from the plane offlange 724 and terminates in an angled portion 762.

Also formed on an outer facing surface 750 of each of arms 726 and 728is an elongate protrusion 764, having tapered forward and rearwardfacing ends 766 and 768 respectively. Forwardly of each protrusion 764there is provided an axial groove 770.

Each of arms 726 and 728 preferably terminates in forward facing surface771 having a tapered forward-facing edge 772 from which extend forwardlya pair of generally axial fingers 774 and 776 having mutually facingforward inwardly directed protrusions 778. A pair of forward-facingprotrusions 780 also extend forwardly of tapered forward-facing edge772.

Reference is now made to FIGS. 29A and 29B, which are simplifiedpictorial illustrations of a plunger element 168, which forms part ofthe reusable driving assembly 110 of the automatic injection device ofFIG. 1, to FIGS. 30A, 30B, 30C and 30D, which are simplified respectivetop, side, front and back views thereof, and to FIGS. 31A and 31B, whichare simplified sectional illustrations taken along respective sectionlines A-A and B-B in FIGS. 30A and 30B.

As seen in FIGS. 29A-31B, the plunger element 168 preferably is anintegrally formed element, preferably injection molded of plastic and isarranged along a longitudinal axis 800. Plunger element 168 includes ata rearward end thereof a generally tubular portion 802 which definesside convex surfaces 804 and 806, and respective top and bottom convexsurfaces 808 and 810, in the sense of FIGS. 29A and 29B. A flexiblesnap-engagement finger 812 is preferably provided on convex surface 808and terminates in an outwardly facing protrusion 814 having aforward-facing surface 816.

Rearwardly of forward-facing surface 816 there are preferably provided apair of side-by-side inclined outwardly facing ribs 818, andtherebetween an inclined outwardly facing rib 820, which is preferablyslightly longer than ribs 818.

A pair of flexible fingers 822 each extend axially rearwardly from aforward edge 823 thereof and outwardly of tubular portion 802 atdiagonally opposite corners thereof and each terminate at an inwardlyfacing protrusion 824 having a tapered rearward edge 826.

A pair of ribs 828 extend axially rearwardly from a forward edge 829thereof and outwardly of tubular portion 802 at diagonally oppositecorners thereof, opposite to fingers 822.

Generally tubular portion 802 terminates forwardly at an inwardly-facingflange 830, which defines a forward facing spring seat for main spring166 (FIG. 1). Extending rearwardly from inwardly-facing flange 830 thereare preferably formed four inwardly directed axial ribs 832, whichtogether with the internal surface of generally tubular portion 802,maintain the concentric orientation of main spring 166 within plungerelement 168.

Extending forwardly from generally convex surfaces 808 and 810 aremounting arms 840, each of which includes at a forward end thereof arearwardly extending flexible finger 842, having a rounded inwardlyfacing protrusion 844.

A pair of axial corner ribs 846 are located at diagonally oppositecorners of mounting arms 840.

A plunger rod 850 is mounted on a base 852, which is in turn supportedon mounting arms 840 and has a rearward-facing surface 854.

Reference is now made to FIGS. 32A and 32B, which are simplifiedpictorial illustrations of rear cover element 170 which forms part ofthe reusable driving assembly 110 of the automatic injection device ofFIG. 1, to FIGS. 33A, 33B. 33C and 33D, which are simplified respectiveside, top, front and back views thereof, and to FIGS. 34A and 34B, whichare simplified sectional illustrations taken along respective sectionlines A-A and B-B in FIGS. 33A and 33B.

As seen in FIGS. 32A-34B, the rear cover element 170 preferably is anintegrally formed element, preferably injection molded of plastic and isarranged along a longitudinal axis 900. Rear cover element 190preferably has a generally rectangular cross-section and includesslightly convex top and bottom walls 902 and 904 in the sense of FIGS.32A & 32B and side walls 906 and 908.

Side walls 906 and 908 are each preferably formed with a convexlongitudinal surface 910, having formed thereon multiple ridges 911,which generally define surfaces which are engaged by a user's fingers.Walls 902, 904, 906 and 908 together terminate at a forward end 912 ofrear cover element 170 at which there are provided a pair of mutuallyadjacent generally circumferential ribs 913.

Walls 902, 904, 906 and 908 together terminate at a rearward end 914 ofrear cover element 170 defining a generally planar rearward facingsurface 915. Cutouts 916 are provided in walls 902 and 904 adjacentrearward end 914 of rear cover element 170.

Forward of cutout 916, wall 902 is formed with mutually axially alignedrespective short and long rectangular apertures 918 and 920, which aretogether partially surrounded by a rib 922 having a profile which ishigher in a forward direction and which tapers to an opening facingrearward end 914. Extending forwardly of aperture 920 to rib 922 is astop surface 924. A transverse support portion 926 separates apertures918 and 920. An inner facing surface 927 of wall 902 lies rearward ofaperture 918.

Wall 902 is preferably formed with a round window 928, which is locatedforwardly of rib 922 and which enables a user to see whether theautomatic injector device is cocked or not.

Extending internally and forwardly from rearward facing surface 915 arefour circularly arranged centering protrusions 930, interiorly of whichare located two snap-fit arms 932, each having an outwardly facingprotrusion 934, and exteriorly of which are located two outerpositioning protrusions 936, each formed with an internally facinggrooves 938. Additionally there are provided two outer snap-fit fingers940, each having an inwardly-facing protrusion 942.

Extending internally and forwardly from rearward facing surface 915 andalong walls 902 and 904 are four longitudinal ribs 943. Extendinginternally and forwardly from rearward facing surface 915 and alongwalls 906 and 908 are four longitudinal ribs 944.

Reference is now made to FIGS. 35A and 35B, which are simplifiedpictorial illustrations of trigger button element 174, which forms partof the reusable driving assembly 110 of the automatic injection deviceof FIG. 1, to FIGS. 36A, 36B and 36C, which are simplified respectiveside, top and front views thereof, and to FIG. 37, which is a simplifiedsectional illustration taken along section line A-A in FIG. 36B.

As seen in FIGS. 35A-37, the trigger button element 174 preferably is anintegrally formed element, preferably injection molded of plastic and isarranged along a longitudinal axis 950. Trigger button element 174includes a main outwardly-facing surface 952, arranged along axis 950.Forward of main outwardly-facing surface 952 there is provided a taperedengagement surface 954, which has an edge configuration which conformsto the inner configuration of rib 922 of rear cover element 170.

Rearward of main outwardly-facing surface 952 there is provided aninward outwardly-facing surface 956, which is joined to mainoutwardly-facing surface 952 by an inwardly extending wall portion 958,having a rearwardly-facing surface 960.

Underlying main outwardly-facing surface 952 and part of engagementsurface 954 is a main inwardly-facing surface 962, forwardly of which isa slightly inclined forward inwardly-facing surface 964. Rearward ofmain inwardly-facing surface 962 there is provided an inwardinwardly-facing surface 966, which is joined to main outwardly-facingsurface 952 by inwardly extending wall portion 958, having aforwardly-facing surface 968.

Extending inwardly from main inwardly-facing surface 962 and inclinedforward inwardly-facing surface 964 are a pair of mutually spacedparallel protrusions 970, each having a forward facing edge 972, aninward facing edge 974 and an inclined inward and rearward facing edge976.

Extending inwardly from main inwardly-facing surface 962, rearwardly ofprotrusions 970 is a transverse upstanding wall 978, which terminates ina rearwardly extending finger 980 having an outer facing surface 982,which faces main inwardly-facing surface 962 and is spaced therefrom andis provided with a protrusion 984 which faces main inwardly-facingsurface 962 and is spaced therefrom.

Reference is now made to FIGS. 38A and 38B, which are simplifiedpictorial illustrations of safety-catch element 176, which forms part ofthe reusable driving assembly 110 of the automatic injection device ofFIG. 1, to FIGS. 39A, 39B and 39C, which are simplified respective side,front and back views thereof, and to FIG. 40, which is a simplifiedsectional illustration taken along section line A-A in FIG. 39A.

As seen in FIGS. 38A-40, the safety-catch element 176 preferably is anintegrally formed element, preferably injection molded of plastic and isarranged along a longitudinal axis 1000. Safety-catch element 176includes a generally tubular portion 1002 from which radially protrude apair of engagement protrusions 1004. Generally tubular portion 1002 hasa rearwardly and inwardly-facing flange 1006 having formed on arearwardly-facing surface 1008 a raised ring protrusion 1010. A pair ofmutually circumferentially-spaced curved cutouts 1012 extend throughflange 1006.

Generally tubular portion 1002 has a forwardly facing edge 1020 whichhas a pair of mutually circumferentially-spaced curved cut-outs 1022,having forward facing cut-out edges 1024.

Extending forwardly from an forward-facing surface 1026 of flange 1006are a pair of generally coaxially, radially-extending ribs 1030, whichjoin an internal circumferential rib 1031 to an interior surface 1032 ofgenerally tubular portion 1002. Internal circumferential rib 1031includes a pair of mutually circumferentially spaced curved cam surfacedefining rib portions 1033, each extending counterclockwise in the senseof FIG. 39B from an interior edge of each of ribs 1030.

Internal circumferential rib 1031 also includes a pair of mutuallycircumferentially spaced generally circular rib portion 1034, each ofwhich follows in a counterclockwise direction a corresponding curved camsurface defining rib portions 1033.

Cam surface defining rib portions 1033 each define a cam surface 1036which extends in a non-circular manner, slightly outwardly of animaginary circular pathway joining generally circular rib portions 1034,which is indicated in FIG. 39B by a circular line 1038.

Each of generally circular rib portions 1034 includes a pair ofoutwardly facing protrusions. The pairs of protrusions are heredesignated by reference numerals 1040 and 1042.

Reference is now made to FIGS. 41A and 41B, which are simplifiedpictorial illustrations of a rear base element 172, which forms part ofthe reusable driving assembly of the automatic injection device of FIG.1, to FIGS. 42A, 42B, 42C and 42D, which are simplified respective side,top, front and back views thereof, and to FIGS. 43A and 43B, which aresimplified sectional illustrations taken along respective section linesA-A and B-B in FIGS. 42A and 42B.

As seen in FIGS. 41A-43B, the rear base element 172 preferably is anintegrally formed element, preferably injection molded of plastic and isarranged along a longitudinal axis 1100. The rear base element 172preferably has a generally rectangular cross-section and includesslightly convex side walls 1102 and 1104 in the sense of FIG. 41A. Eachof side walls 1102 and 1104 has a long rectangular slot 1106, having aforward edge 1107, and, rearwardly thereof, a short rectangular slot1108 having a forward edge 1109. Each of side walls 1102 and 1104 alsoincludes a narrow slot 1110, having a forward edge 1111. Interiorly ofeach of side walls 1102 and opposite narrow slot 1110 there ispreferably provided an inwardly-directed axially extending rib 1112.

The rear base element 172 also includes top and bottom walls 1113 and1114 respectively, each of which include an elongate slot 1116 having arelatively widened portion 1118, a relatively narrow forward portion1120 and a relatively narrow rearward portion 1122. A forward end ofrelatively narrow forward portion 1120 is separated from a forwardfacing edge 1123 of rear base element 172 by a transverse portion 1124.An inwardly directed rib 1126 extends along part of one side of rearwardportion 1122. Relatively widened portion 1118 defines a rearward edge1127.

The rear base element 172 preferably defines along interior wallsurfaces of respective side walls 1102 and 1104, elongate plunger travelguiding surfaces 1128.

The rear base element 172 terminates at a rearward end thereof in an endportion 1129 having a wall 1130, from a forwardly-facing surface 1131 ofwhich extends forwardly a circular cylindrical tubular portion 1132having four radially and longitudinally extending ribs 1134 extendingoutwardly therefrom and having forward facing edges 1135. Wall 1130 alsodefines a forward-facing shoulder 1136 interiorly of circularcylindrical tubular portion 1132. Tubular portion 1132 has a forwardfacing circumferential edge 1138.

A pair of side-to-side symmetric fingers 1140 extend backwardly fromsides of cylindrical tubular portion 1132. Each of fingers 1140 includesa longitudinal portion 1142 which terminates a rearwardly- andoutwardly-directed portion 1144. An undercut 1146 is defined by thejunction between portions 1142 and 1144. Rearwardly- andoutwardly-directed portion 1144 defines an outwardly-directed protrusion1148 including a forwardly-facing tapered edge 1150 and a rearwardoutwardly-facing surface 1152.

A pair of circular partially circumferential ribs 1154 extend rearwardlyfrom wall 1130. Each of ribs 1154 has a counterclockwise facing taperededge 1156, in the sense of FIG. 42D.

A short tubular portion 1160, of generally rectangular cross section,also extends rearwardly from wall 1130 and terminates in a pair ofrearward-facing protrusions 1162.

Wall 1130 is formed with a pair of mutually 180-degree spaced apertures1164.

The foregoing describes the various elements of the automatic injectiondevice of FIG. 1. The description which follows explains how the variouselements of the automatic injection device of FIG. 1 cooperate invarious operative orientations of the device.

Reference is now made to FIG. 44, which is a simplified assembled viewillustration of the reusable driving assembly 110 of the automaticinjection device of FIG. 1 in a storage operative orientation, to FIGS.45A and 45B, which are simplified respective side and top views thereof,and to FIGS. 46A, 46B, 46C, 46D. 46E and 46F, which are simplifiedsectional illustrations taken along respective section lines A-A, B-B,C-C, D-D, E-E and F-F in FIGS. 45A and 45B.

As seen in FIGS. 44A-46C, in the storage operative orientation theforward cover element 158 is partially inserted in the rear coverelement 170 along mutually coaxial axes 650 and 900. The extent ofpartial insertion is indicated by the fact that the forward end 912 ofthe rear cover element 170 lies generally along actuatable operativeorientation indicating circumferentially extending line 712.

Details of the relative operative orientations of the various elementsof the reusable driving assembly 110 of the automatic injection deviceof FIG. 1 in the storage operative orientation will now be describedwith reference to FIGS. 47-55.

Reference is now made to FIG. 47, which is a simplified side viewillustration in the sense of FIGS. 44-46C of an assembly including theforward cover element 158 (FIGS. 22A-25B), the needle penetration depthselector 152 (FIGS. 17A-19) and the forward base element 150 (FIGS.14A-16B). Reference is also made to FIGS. 48A, 48B and 48C, which aresimplified cross-sectional illustrations taken along respective linesA-A, B-B and C-C in FIG. 47 and FIG. 48D is a pictorial cross-sectionalillustration taken along lines C-C in FIG. 47.

As seen in FIGS. 47-48D, the needle penetration depth selector 152(FIGS. 17A-19) is located within the forward cover element 158, suchthat its longitudinal axis 550 is coaxial with longitudinal axis 650 offorward cover element 158 and positioned therealong such that itprotrudes through cutouts 680 formed in forward cover element 158. Morespecifically forward circumferential protrusion 554 lies adjacentforward edges of cutouts 680.

It is seen that snap engagement protrusions 704 of the forward coverelement 158 are preferably located in two of four rearward-facingcircumferentially distributed recesses 558 of needle penetration depthselector 152, depending on the rotational position of the needlepenetration depth selector 152 about axes 550 and 650.

The forward base element 150 is arranged such that its longitudinal axis400 is coaxial with axes 550 and 650 and is positioned transversely toaxes 550 and 650 with respect to the forward cover element 158 and toneedle penetration depth selector 152 by engagement of forward cornerprotrusions 456 and 458 of forward base element with internally facingribs 710 of forward cover element 158.

The axial position of forward base element 150 relative to forward coverelement 158 is selectably variable within predetermined limits, as afunction of rotation of needle penetration depth selector 152 about axis550 due to engagement of outwardly extending protrusions 404 and 406 offorward base element 150 with respective helical internal threadings 560and 562 of needle penetration depth selector 152. Rotation of forwardbase element 150 about axes 400, 550 and 650 is prevented by theaforesaid engagement of forward corner protrusions 456 and 458 offorward base element with internally facing ribs 710 of forward coverelement 158. The axial position of forward base element 150 relative toforward cover element 158 along axes 400, 550 and 650 is indicated byouter facing rib 446 of forward base element 150, which rib which can beviewed through windows 676 of forward cover element 158, relative toneedle depth setting scale 678 appearing alongside windows 676.

A pair of tabs 702 of forward cover element 158 engage rectangular slots492 of forward base element 150.

Reference is now made to FIGS. 49A and 49B, which are simplifiedrespective side and top views, in the sense of FIGS. 44-46D, of anassembly of needle guard deploying spring 160, needle guard deployingelement 162 (FIGS. 26A-28B) and rear base element 172 (FIGS. 41A-43B).Reference is also made to FIGS. 50A and 50B, which is simplifiedrespective sectional illustrations taken along lines A-A and B-B in FIG.49A.

As seen in FIGS. 49A-50B, needle guard deploying spring 160 and needleguard deploying element 162 are both disposed within rear base element172 such that the longitudinal axis of spring 160 is coaxial withrespective longitudinal axes 720 and 1100 of needle guard deployingelement 162 and rear base element 172. Spring 160 is seated at arearward end thereof on forwardly-facing surface 1131 of rear baseelement 172 and is seated at a forward end thereof on circumferentialflange 724 of needle guard deploying element 162 and urges the needleguard deploying element 162 forwardly. Needle guard deploying element162 is retained against forward displacement when in the storageoperative orientation by engagement of fingers 744 thereof withcorresponding narrow slots 1110 of rear base element 172.

Reference is now made to FIG. 51, which is a simplified side view, inthe sense of FIGS. 44-46D, of an assembly of rear cover element 170(FIGS. 32-34B), trigger button element 174 (FIGS. 35A-37) and safetycatch element 176 (FIGS. 38A-40). Reference is also made to FIGS. 52Aand 52B, which are simplified respective planar and pictorialcross-sectional view both taken along lines A-A in FIG. 51. Reference isalso made to FIG. 53, which is a simplified cross-sectional view takenalong lines B-B in FIG. 51.

As seen in FIGS. 51-53, the safety catch element 176 is located withinthe rear cover element 170, such that it's longitudinal axis 1000 iscoaxial with longitudinal axis 900 of rear cover element 170.Longitudinal ribs 944 of the rear cover element 170 engage tubularportion 1002 of the safety catch element 176 for centering thereof aboutlongitudinal axis 1000. Inwardly-facing protrusions 942 of rear coverelement 170 engage forward facing cut-out edges 1024 of curved cut-outs1022 of the safety catch element 176 and are operative to preventforward displacement and limit rotation of the safety catch element 176about axes 900 and 1000.

Outwardly facing protrusions 1040 of the safety catch element 176 engagea pair of internally facing grooves 938 formed in corresponding outerpositioning protrusions 936 of rear cover element 170. This engagementensures that in the storage operative orientation, the safety catchelement 176 is in a disengaged operative orientation.

The positioning of trigger button element 174 relative to rear coverelement 170 in the storage operative orientation is seen to be asfollows:

Inward outwardly-facing surface 956 of trigger button element 174underlies inner facing surface 927 of wall 902. Transverse supportportion 926 of the rear cover element 170 is engaged by trigger buttonelement 174 in a socket defined by main inwardly facing surface 962,transverse upstanding wall 978, rearwardly-extending finger 980 andprotrusion 984 of trigger button element 174.

Reference is now made to FIGS. 54A and 54B which are simplifiedrespective side and top view illustrations of an assembly which includesthe assembly of FIGS. 49A-50B mounted within the assembly of FIGS. 51-53such that axes 720, 900, 1000 and 1100 are all mutually coaxial.Reference is also made to FIG. 55, which is a simplified sectionalillustration taken along lines A-A in FIG. 54B. The assembly of FIGS.54A-55 also includes injection site engagement sensing spring 178 (FIG.1), which urges the rear base element 172 forwardly along mutuallycoaxial axes 720, 900, 1000 and 1100.

As seen in FIGS. 54A-55, protrusions 934 of snap-fit arms 932 of rearcover element 170 engage forward-facing shoulder 1136, locatedinteriorly of circular cylindrical tubular portion 1132 of rear baseelement 172. This engagement prevents spring 178 from displacing rearbase element 172 forwardly.

Returning now to FIGS. 44-46F, it is seen that main spring 166 andplunger element 168 are assembled together with the assembly of FIGS.54A-55 such that the longitudinal axis of the main spring 166 and thelongitudinal axis 800 of plunger element 168 are coaxial with axes 720,900, 1000 and 1100.

It is also seen that the cocked orientation retaining elements 154 andcocking springs 156 are assembled together with the assembly of FIGS.47-48D.

The combined assembly of FIGS. 44-46F is arranged such that all of axes400, 550, 650, 720, 800, 900, 1000 and 1100 are mutually coaxial.

With particular reference to FIG. 46B, it can be seen that snapengagement finger 812 is located forwardly of trigger button element174.

With particular reference to FIGS. 44 and 46A, it is noted that cockedorientation retaining elements 154 engage respective rearward facingedges 682 and 684 of the forward cover element 158 such thatforward-facing protrusions 614 of cocked orientation retaining elements154 lie in notches 690 formed in respective rearward facing edges 682and 684 of the forward cover element 158, whereby the axis 620 of eachof cocked orientation retaining elements 154 is coaxial with acorresponding axis 691 of one of respective rearward facing edges 682and 684 of the forward cover element 158.

It is also noted that cocking springs 156 are each attached at arearward end thereof to a corresponding hook 610 of a cocked orientationretaining element 154. Cocked springs 156 are each attached at a forwardend thereof to a corresponding transverse portion 1124 of rear baseelement 172. Cocking springs 156 thus extend along respective tensioningaxes 1170 and 1172, which extend transversely relative to coaxial axes620 and 691 and thus apply a rotational moment to respective cockedorientation retaining elements 154 about coaxial axes 620 and 691,urging rotation of cocked orientation retaining elements 154 in adirection such that rearward facing end portions 604 are urged inwardly.

Inward displacement of rearward facing end portions 604 does not takeplace when the reusable driving assembly 110 is in the storage operativeorientation due to engagement of hooks 610 of cocked orientationretaining elements 154 with corresponding elongate protrusions 764 ofneedle guard deploying element 162.

It is further appreciated that due to the engagement of hooks 610 withcorresponding elongate protrusions 764 of needle guard deploying element162, rearward ends 607 of cocked orientation retaining elements 154 lieoutwardly of relatively widened portion 1118 of rear base element 172,thereby permitting relative longitudinal axial displacement of cockedorientation retaining elements 154, thus enabling relative longitudinalaxial displacement of the forward cover element 158 and the rear coverelement 170.

With particular reference to FIG. 46B, it is seen that rear base element172 is slidably engaged with forward cover element 158 and the rearwarddisplacement of rear base element 172 relative to forward cover element158 is limited by engagement of internally facing protrusions 706 of theforward cover element 158 with slots 1106 of rear base element 172 andmore specifically with forward edges 1107 of slots 1106.

With particular reference to FIGS. 46A-46C, 46E and 46F, it is notedthat main spring 166 is seated at a rearward end thereof on forwardedges 1135 of ribs 1134 of rear base element 172 and surrounds tubularportion 1132. A forward end of main spring 166 is seated on flange 830of plunger element 168. Plunger element 168 is partially located withinrear base element 172 wherein ribs 828 and fingers 822 of plungerelement 168 slidably engage plunger travel guiding surfaces 1128 of rearbase element 172.

Mounting arms 840 of plunger element 168 engage corresponding internalelongate recesses 500 and 501 of forward base element 150.Forward-facing edges 823 and 829 of respective fingers 822 and ribs 828engage the rearwardmost edge 440 of forward base element 150. As notedabove with reference to FIGS. 47-48D, the forward displacement offorward base element 150 relative to forward cover element 158 islimited via engagement with the needle penetration depth selector 152.Accordingly, in the storage operative orientation, the forwarddisplacement of plunger element 168 relative to forward cover element158 along axis 1100 in response to urging of main spring 166, which ispreferably partially compressed, is limited, to an extent selected by auser employing the needle penetration depth selector 152.

With particular reference to FIG. 46C, it is seen that axial fingers 774and 776 of needle guard deploying element 162 are in a relative openorientation in the storage operative orientation of the reusable drivingassembly 110.

With particular reference to FIG. 45A, it is seen that in the storageoperative orientation, the main spring 166 is viewable via round window928, indicating that the reusable driving assembly 110 is not cocked. Itis also seen in FIG. 45A and in FIG. 46F that the safety catch element176 is in a disengaged operative orientation, which does not preventinjection. As will be described hereinbelow, in other operativeorientations, the safety catch element 176 is in an engaged operativeorientation.

In the storage operative orientation, as required, the user sets thedesired needle penetration depth by rotation of the needle penetrationdepth selector element 152. Four needle penetration depth settings aretypically provided: 6 mm, 8 mm, 10 mm and 12 mm, where rotation of theneedle penetration depth selector element 152 by 90° is required to movebetween one setting to the next. The user can observe the currentsetting through windows 676 at both sides of the injector, thus allowingboth right-handed and left-handed users to easily observe the needledepth setting during rotation.

It is appreciated that needle penetration depth selection can becustomized either for different depth settings, or obviated.

Reference is now made to FIG. 56, which is a simplified assembled viewillustration of the reusable driving assembly 110 of the automaticinjection device of FIG. 1 in a cocking operative orientation, to FIGS.57A and 57B, which are simplified respective side and top views thereof,and to FIGS. 58A, 58B, 58C and 58D, which are simplified sectionalillustrations taken along respective section lines A-A, B-B, C-C and D-Din FIGS. 57A and 57B.

The cocking operative orientation seen in FIGS. 56-58D is preferablyrealized by a user taking the reusable driving assembly 110 in itsstorage operative orientation, as seen in FIGS. 44-55 and rotatingsafety catch element 176 by engaging engagement protrusions 1004, sothat it is in a safety catch engaged operative orientation. The user,holds the reusable driving assembly 110 in one hand, by grasping therear cover element 170. The user, while grasping the rear cover element170, applies an axial force along axes 650 and 900 forcing forward edge671 of the forward cover element 158 against a surface 1200, causingtensioning of cocking springs 156 and compression of main spring 166.

As seen in FIGS. 56-58D, in the cocking operative orientation, theforward cover element 158 is nearly fully inserted in the rear coverelement 170 along mutually coaxial axes 650 and 900. The extent ofinsertion in the cocking operative orientation is generally seen in FIG.58B, and is limited by engagement of forward facing circumferential edge1138 of tubular portion 1132 of rear base element 172 with back surface854 of base 852 of plunger element 168.

With particular reference to FIG. 58B, it can be seen that snapengagement finger 812 of plunger element 168 underlies trigger buttonelement 174 and finger 812 is in engagement with forward edge 1109 ofslot 1108 in rear base element 172, thereby retaining plunger element168 in a cocked operative orientation.

With particular reference to FIG. 58C, it can be seen that in the cockedoperative orientation, that the inwardly facing protrusions 824 offlexible fingers 822 of plunger element 168 are urged towards each otherby engagement thereof with inwardly-directed axially extending ribs 1112of rear base element 172.

With particular reference to FIG. 56, it can be seen that in the cockedoperative orientation, cocked orientation retaining elements 154 arerearwardly displaced relative to widened portion 1118 of elongate slot1116 of rear base element 172, as compared with their operativeorientation in the storage operative orientation and are locatedadjacent a rearward end of rearward portion 1122 of slot 1116.

Reference is now made to FIG. 59, which is a simplified assembled viewillustration of the reusable driving assembly 110 of the automaticinjection device of FIG. 1 in a cocked operative orientation, to FIGS.60A and 60B, which are simplified respective side and top views of thereusable driving assembly 110 and of disposable cassette assembly 100arranged coaxially therewith ready for insertion thereinto, and to FIGS.61A, 61B, 61C and 61D, which are simplified sectional illustrationstaken along respective section lines A-A, B-B, C-C and D-D in FIGS. 60Aand 60B.

The cocked operative orientation seen in FIGS. 59-61D is preferablyrealized by a user taking the reusable driving assembly 110 in itscocking operative orientation, as seen in FIGS. 56-58D. The user,holding the reusable driving assembly 110 in one hand, by grasping therear cover element 170 releases the axial force earlier applied alongaxes 650 and 900 by distancing forcing forward edge 671 of the forwardcover element 158 from a surface 1200, thereby allowing tensionedcocking springs 156 to displace forward cover element 158 forwardly toits relative orientation vis a vis the rear cover element 170 in thestorage operative orientation.

With particular reference to FIG. 61C, it is seen that engagement offorward-facing surfaces 748 of fingers 744 of needle guard deployingelement 162 with forward edges 1111 of narrow slots 1110 formed in rearbase element 172, retains needle guard deploying element 162 againstforward displacement against the urging of needle guard deploying spring160.

As a result elongate protrusions 764 of needle guard deploying element162 are positioned rearwardly of hooks 610 of cocked orientationretaining elements 154. This orientation enables rearward displacementof forward cover element 158 relative to rear cover element 170 to beprevented by engagement of rearward ends 607 of cocked orientationretaining elements 154 with rearward edge 1127 of rear base element 172.

The engagement of rearward ends 607 of cocked orientation retainingelements 154 with rearward edge 1127 of rear base element 172 resultsfrom application by cocking springs 156 of a rotational moment torespective cocked orientation retaining elements 154 about coaxial axes620 and 691, urging rotation of cocked orientation retaining elements154 in a direction such that rearward facing end portions 604 are urgedinwardly.

Forward displacement of forward cover element 158 relative to rear baseelement 172 is limited by engagement of internally facing protrusions706 of the forward cover element 158 with slots 1106 of rear baseelement 172 and more specifically with forward edges 1107 of slots 1106.

With particular reference to FIG. 60A, it is appreciated that plungerelement 168 can be seen through round window 928.

With particular reference to FIG. 60B, it is appreciated that if triggerbutton element 174 is inadvertently depressed when the reusable drivingassembly 110 is in the cocked operative orientation, it will engage stopsurface 924 and will thus not engage flexible finger 812 of plungerelement 168 and thus will not release the plunger inadvertently.

With particular reference to FIGS. 61A & 61C, it is seen that axialfingers 774 and 776 of needle guard deploying element 162 are still in arelative open orientation in the cocked operative orientation of thereusable driving assembly 110.

Outwardly facing protrusions 1042 of the safety catch element 176 engageinternally facing grooves 938 formed in corresponding outer positioningprotrusions 936 of rear cover element 170. This engagement ensures thatradially extending ribs 1030 of safety catch element 176 engagecircumferential ribs 1154 of rear base element 172 and thus preventrearward displacement of rear base element 172 relative to rear coverelement 170.

It is appreciated that the mutual rotational orientation of the reusabledriving assembly 110 and the disposable cassette assembly 100 whenarranged coaxially therewith ready for insertion thereinto as seen inFIGS. 59-61D are preferably as follows:

As seen in FIG. 61A, rearward-facing flat protrusions 212 and 214 ofcassette housing element 120 of disposable cassette assembly 100 arealigned along respective axes 1250 and 1252 which are tangential torespective axes 1260 and 1262 of tabs 702 of the forward cover element158.

As seen in FIG. 61C, tracks 252 & 254 and 250 & 256 formed in cassettehousing element 120 of disposable cassette assembly 100 are aligned withrespect to respective protrusions 696 of forward cover element 158 andinternally-facing ribs 530 of forward base element 150, of reusabledriving assembly 110, such that one of protrusions 696 and one ofinternally-facing ribs 530 is aligned along an axis which is coaxialwith an axis of one of tracks 250 and 252 and another of protrusions 696and another of internally-facing ribs 530 is aligned along an axis 1280which is coaxial with an axis of one of tracks 254 and 256.

Reference is now made to FIG. 62, which is a simplified assembled viewillustration of the reusable driving assembly 110 of the automaticinjection device of FIG. 1 in a pre-injection operative orientation,having the disposable cassette assembly 100 fully inserted therein alongmutually coaxial axes 362 and 390 and the needle shield remover 140 andthe needle shield 130 removed from the disposable cassette assembly 100;to FIGS. 63A and 63B, which are simplified respective side and top viewsthereof, and to FIGS. 64A, 64B and 64C, which are simplified sectionalillustrations taken along respective section lines A-A, B-B and C-C inFIGS. 63A and 63B.

Full engagement and retention of disposable cassette assembly 100 inreusable driving assembly 110 is provided by:

-   -   engagement of forwardly-facing shoulders 742 of fingers 738 of        needle guard deploying element 162 with corresponding inwardly        facing protrusions 824 of flexible fingers 822 of plunger        element 168; and    -   engagement of inwardly directed protrusions 778 of fingers 774        and 776 of needle guard deploying element 162 of reusable        driving assembly 110 with corresponding notches 320 of needle        guard element 122 of disposable cassette assembly 100.

Engagement of inwardly directed protrusions 778 of fingers 774 and 776of needle guard deploying element 162 of reusable driving assembly 110with corresponding notches 320 of needle guard element 122 of disposablecassette assembly 100 is enabled by rearward displacement of needleguard deploying element 162, which is urged rearwardly by axialinsertion of the disposable cassette assembly, causing engagement ofrearward facing edges 312 and 314 of mounting arms 308 and 310 of needleguard element 122 of the disposable cassette assembly with forwardfacing surface 771 of needle guard deploying element 162 of reusabledriving assembly 110, against the urging of needle guard deployingspring 160.

It is noted that in order for the disposable cassette assembly 100 to beretained in the reusable driving assembly 110 the following conditionsmust be fulfilled:

-   -   The safety catch element 176 must be in the safety catch engaged        operative orientation. As seen particularly in FIG. 64B, when        the safety catch element 176 is in the safety catch engaged        operative orientation, cam surfaces 1036 urge rearward outwardly        facing surfaces 1152 of fingers 1140 of rear base element 172        inwardly and thus undercuts 1146 are not engaged by protrusions        734 of needle guard deploying element 162 and thus permit full        rearward displacement of needle guard deploying element 162 to        an extent that enables forwardly-facing shoulders 742 of fingers        738 of needle guard deploying element 162 to engage with        corresponding inwardly facing protrusions 824 of flexible        fingers 822 of plunger element 168; and    -   Inwardly-facing protrusions 778 of fingers 774 and 776 are        forced inwardly by engagement of fingers 774 and 776 with        internally facing ribs 510 and 512 of forward base element 150.

Once the disposable cassette assembly 100 is retained in the reusabledriving assembly 110, a user can readily remove the needle shieldremover 140 together with the needle shield 130 by pulling it axially ina direction 1290 along axis 362.

With particular reference to FIG. 64C it is seen that insertion andretention of the disposable cassette assembly 100 in reusable drivingassembly 110 cause disengagement of outwardly-facing protrusions 340 inneedle guard element 122 from corresponding forward slots 260 and 262 incassette housing element 120. This disengagement is the result ofengagement of internally-facing ribs 530 of forward base element 150 ofreusable driving assembly 110 with protrusions 340.

Reference is now made to FIG. 65, which is a simplified assembled viewillustration of the reusable driving assembly 110 of the automaticinjection device of FIG. 1 in an injection site engagement operativeorientation; to FIGS. 66A and 66B, which are simplified respective sideand top views thereof, and to FIGS. 67A, 67B and 67C, which aresimplified sectional illustrations taken along respective section linesA-A, B-B and C-C in FIGS. 66A and 66B.

The injection site engagement operative orientation seen in FIGS. 65-67Cis preferably realized by a user taking the reusable driving assembly110 in pre-injection operative orientation, as seen in FIGS. 62-64C androtating safety catch element 176 by engaging engagement protrusions1004, so that it is in the disengaged operative orientation. The userholds the reusable driving assembly 110 in one hand, by grasping therear cover element 170. The user, while grasping the rear cover element170, applies an axial force along axes 390, 650 and 900 forcing theforward-facing injection site rings 304 and 306 of the needle guardelement 122 of the disposable cassette assembly 100 and potentially alsoforward edge 671 of the forward cover element 158 against an injectionsite surface 1300, such as skin, causing compression of injection siteengagement sensing spring 178.

In the injection site engagement operative orientation, as seenparticularly in FIG. 67B, radially extending ribs 1030 of safety catchelement 176, as particularly seen in FIG. 39B, do not engagecircumferential ribs 1154 of rear base element 172 and thus do notprevent rearward displacement of rear base element 172 relative to rearcover element 170.

With particular reference to FIG. 66B, it is seen that in the injectionsite engagement operative orientation, with the safety catch element 176in the disengaged operative orientation, if trigger button element 174is depressed when the reusable driving assembly 110 is in the injectionsite engagement operative orientation, trigger button element 174 willengage flexible finger 812 of plunger element 168, thus causing forwardedge 816 of flexible finger 812 to disengage from forward edge 1109 ofrectangular slot 1108 of rear base element 172, thereby allowing forwarddisplacement of plunger element 168 and corresponding forwarddisplacement of syringe 124.

In the injection site engagement operative orientation, as seenparticularly in FIGS. 65, 66A and 66B, the orientation indicatingcircumferentially extending line 712 is preferably not visible, thusindicating to the user that injection may be initiated by pressing ontrigger button element 174.

It is appreciated that forward displacement of the syringe 124 islimited by engagement of forward facing edges 268 and 280 of cassettehousing element 120 with rearward facing edges 356 of finger portions328 and 338 of the needle guard element 122. Axial corner ribs 846 ofplunger element 168 are positioned rearwardly with respect torearward-facing tapered surfaces 354 of protrusions 350 of fingerportions 328 and 338 of the needle guard element 122.

Reference is now made to FIG. 68, which is a simplified assembled viewillustration of the reusable driving assembly 110 of the automaticinjection device of FIG. 1 in a needle insertion operative orientation;to FIGS. 69A and 69B, which are simplified respective side and top viewsthereof, and to FIGS. 70A, 70B and 70C, which are simplified sectionalillustrations taken along respective section lines A-A, B-B and C-C inFIGS. 69A and 69B.

The needle insertion operative orientation shown in FIGS. 68-70C is theoperative orientation resulting from depression of the trigger buttonelement 174 when the reusable driving assembly 110 is in the injectionsite engagement operative orientation. Trigger button element 174engages flexible finger 812 of plunger element 168, thus causing forwardedge 816 of flexible finger 812 to disengage from forward edge 1109 ofrectangular slot 1108 of rear base element 172 which results in forwarddisplacement of plunger element 168 and corresponding forwarddisplacement of syringe 124 under the urging of main spring 166.

With particular reference to FIG. 70B, it is seen that main spring 166,which is under partial compression, urges plunger element 168 forwardly,causing inwardly-facing protrusions 844 of flexible fingers 842 of theplunger element 168. Forward axial displacement of the syringe 124 alongaxes 390 and 650 is limited by engagement of flange 126 with rearwardedges 202 of cassette housing element 120 and by engagement of fingerportions 216 and 218 of cassette housing element 120 with inwardlytapered surfaces 486 and 488 of forward base element 150 which weredisengaged from respective slots 316 of needle guard element 122 byengagement of forward facing tapered surfaces 318 of needle guardelement 122 with protrusions 220 of finger portions 216 and 218 ofcassette housing element 120. It is appreciated that the axial locationof inwardly tapered surfaces 486 and 488 of forward base element 150 isdetermined by the setting of the needle penetration depth selector 152.

It is appreciated that in the needle insertion operative orientation ofFIGS. 68-70C, injection of liquid via needle 128 has not yet occurred,inasmuch as plunger rod 850 is not yet engaged with the piston 125 ofsyringe 124. It is seen that flexible fingers 842 of plunger element168, whose outwardly lateral displacement was previously prevented byengagement with side walls 416 and 418 of forward base element 150, nowlie opposite respective rearward slots 436 and 438.

It is appreciated that forward displacement of the syringe 124 wasenabled by inward displacement of protrusions 350 of finger portions 328and 338 of the needle guard element 122 due to engagement thereof bycorner ribs 846 of plunger element 168 during forward displacementthereof.

Reference is now made to FIG. 71, which is a simplified assembled viewillustration of the reusable driving assembly 110 of the automaticinjection device of FIG. 1 in an end-of-injection operative orientation;to FIGS. 72A and 72B, which are simplified respective side and top viewsthereof, and to FIGS. 73A, 73B and 73C, which are simplified sectionalillustrations taken along respective section lines A-A. B-B and C-C inFIGS. 72A and 72B.

It is seen in FIGS. 73A-73C that plunger rod 850 of plunger element 168,which was urged forwardly by main spring 166, engaged piston 125 inorder to inject liquid 131 contained in syringe 124 into the injectionsite 1300.

Reference is now made to FIG. 74, which is a simplified assembled viewillustration of the reusable driving assembly 110 of the automaticinjection device of FIG. 1 in a post-injection operative orientation; toFIGS. 75A and 75B, which are simplified respective side and top viewsthereof, and to FIGS. 76A, 76B and 76C, which are simplified sectionalillustrations taken along respective section lines A-A, B-B and C-C inFIGS. 75A and 75B.

It is seen that the automatic injection device is disengaged from theinjection site 1300 by the user. As the forward-facing injection siterings 304 and 306 are separate from the injection site, the needle guardelement 122 emerges forwardly from axial opening 694 to surround theneedle 128, such that the needle 128 is at all times substantiallyprotected from finger engagement and the user is protected frominadvertent needle stick.

The forward displacement of the needle guard element 122 results fromthe following events:

Injection site engagement, as shown in FIGS. 65-67C, causes protrusions732 of flexible fingers 730 of needle guard deploying element 162 toextend rearwardly through apertures 1164 in end portion 1129 of rearbase element 172. Protrusions 732 engage wall 1130 of end portion 1129and are locked thereto by engagement therewith of circular rib portions1034 of safety catch element 176. This locking engagement preventsforward displacement of needle guard deploying element 162 as long asthe automatic injection device is pressed against the injection site, asseen in FIGS. 65-73C.

Once the automatic injection device is no longer pressed against theinjection site, circular rib portions 1034 of safety catch element 176no longer engage end portion 1129, thus allowing protrusions 732 to bedisplaced forwardly through apertures 1164 and out of engagement withwall 1130 of rear base element 172. Under the urging of needle guarddeploying spring 160, the needle guard deploying element 162 movesaxially forwardly and pushes the needle guard element 122 forwardly offorward edge 671 of forward cover element 158, thus enabling the needleguard element 122 to surround the exposed needle 128.

Forward displacement of needle guard element 122 is limited byengagement of outward-facing protrusions 746 of fingers 744 of needleguard deploying element 162 with forward edges 1111 of narrow slots1110.

The cassette housing element 120 is axially locked to needle guardelement 122 by engagement of protrusions 350 of fingers 328 and 338 withslots 266 and 264 respectively.

The disposable cassette assembly 100 is meanwhile weakly retainedagainst removal from the reusable driving assembly 110 by engagement ofprotrusions 340 of finger portions 326 and 336 with protrusions 696 offorward cover element 158.

Removal of the disposable cassette assembly 100 from the reusabledriving assembly 110 is readily achieved by a user pulling axially onthe disposable cassette assembly 100 in a direction 1350 along axes 390and 650, thereby causing disengagement of protrusions 340 of fingerportions 326 and 336 with protrusions 696 of forward cover element 158.

Once the disposable cassette assembly 100 has been removed from thereusable driving assembly 110, the amount of liquid 131 remaining in thesyringe 124 can readily be visually ascertained, by viewing the interiorof the syringe 124 via either of windows 204.

It will be appreciated by persons skilled in the art that the presentinvention is not limited by what has been specifically shown anddescribed hereinabove. Rather the scope of the invention includes bothcombinations and sub-combinations of features described and shownhereinabove as well as modifications thereof which would occur topersons reading the foregoing description and which are not in the priorart.

The invention claimed is:
 1. An automatic injection device comprising: a reusable driving assembly having a needle insertion operative orientation; and a disposable cassette assembly comprising a cassette housing element, a prefilled syringe including a needle, a needle shield mounted onto said needle and a needle guard element, said needle shield is configured to be removed from said disposable cassette assembly before said reusable driving assembly assumes said needle insertion operative orientation; said cassette housing element and said needle guard element being arranged such that prior to both said disposable cassette assembly having been inserted into said reusable driving assembly and said reusable driving assembly being in said needle insertion operative orientation, relative axial displacement between said cassette housing element and said needle guard element is prevented due to locking between said needle guard element and said cassette housing element, and wherein said needle protrudes from a forward end of said needle guard when said reusable driving assembly is in said needle insertion operative orientation, and wherein displacement of said cassette housing element relative to said needle guard element is permitted while said reusable driving assembly is in said needle insertion operative orientation when said needle guard element is pressed against the injection site, and wherein only following insertion and retention of said disposable cassette assembly in said reusable driving assembly, said reusable driving assembly may be caused to assume said needle insertion operative orientation by pressing a trigger button element, thereby causing forward axial displacement of said cassette housing element and resulting penetration of an injection site by said needle.
 2. An automatic injection device according to claim 1 and wherein said arrangement of said cassette housing element and said needle guard element is such that said relative axial displacement between said cassette housing element and said needle guard element is prevented by a first engagement and a second engagement causing temporary locking between said cassette housing element and said needle guard element, said first engagement being released upon insertion of said disposable cassette assembly into said reusable driving assembly and said second engagement being released when said reusable driving assembly is in said needle insertion operative orientation, which is caused by pressing a trigger button element.
 3. An automatic injection device according to claim 2 and wherein said first engagement is provided by mutual engagement of at least one first protrusion of said needle guard element with at least one first slot of said cassette housing element and said second engagement is provided by mutual engagement of at least one second protrusion of said needle guard element with at least one second slot of said cassette housing element.
 4. An automatic injection device according to claim 1 and wherein: said disposable cassette assembly has a pre-use operative orientation, which is suitable for storage; in said pre-use operative orientation, said needle guard element is locked to said cassette housing element by snap fit engagement of at least one protrusion of said needle guard element in at least one slot formed in said cassette housing element.
 5. An automatic injection device according to claim 1 and wherein: said reusable driving assembly includes a forward injection end and multiple mutually axially displaceable elements; said needle is suitable for injecting an injectable liquid at an injection site; said disposable cassette assembly is removably insertable into said reusable driving assembly at said forward injection end; and following insertion of said disposable cassette assembly into said reusable driving assembly, said automatic injection device may be caused to assume an injection site engagement operative orientation by pressing said forward injection end of said reusable driving assembly against said injection site, thereby producing mutual axial displacement of at least some of said multiple mutually axially displaceable elements but not producing relative axial displacement between said needle guard element and said cassette housing element of said disposable cassette assembly.
 6. An automatic injection device according to claim 1 and wherein: following insertion of said disposable cassette assembly into said reusable driving assembly, said reusable driving assembly may be caused to assume an injection site engagement operative orientation; and following assumption of a pre-needle insertion operative orientation, said reusable driving assembly may be caused to assume said needle insertion operative orientation by pressing a trigger button element, thereby causing forward axial displacement of said cassette housing element and resulting penetration of said injection site by said needle to a penetration depth defined by engagement of said cassette housing element with a forward base element of said reusable driving assembly.
 7. An automatic injection device according to claim 1 and wherein: following injection, said disposable cassette assembly extends partially outside of said reusable driving assembly at a forward injection end thereof and is releasably retained in said reusable driving assembly; and said disposable cassette assembly may thereafter be fully disengaged from said reusable driving assembly by axially pulling said disposable cassette assembly out of said reusable driving assembly.
 8. An automatic injection device comprising: a reusable driving assembly having a forward injection end and multiple mutually axially displaceable elements; and a disposable cassette assembly including a cassette housing element, a prefilled syringe including a needle for injecting an injectable liquid at an injection site and a needle guard element, wherein: said disposable cassette assembly is removably insertable into said reusable driving assembly at said forward injection end; following insertion of said disposable cassette assembly into said reusable driving assembly, said automatic injection device may be caused to assume an injection site engagement operative orientation by pressing said forward injection end of said reusable driving assembly against said injection site, thereby producing mutual axial displacement of at least some of said multiple mutually axially displaceable elements but not producing relative axial displacement between said needle guard element and said cassette housing element of said disposable cassette assembly.
 9. An automatic injection device according to claim 8 and wherein: said reusable driving assembly includes a forward base element and a trigger button element; following assumption of said injection site engagement operative orientation, said automatic injection device may be caused to assume a needle insertion operative orientation by pressing said trigger button element, thereby causing forward axial displacement of said cassette housing element and resulting penetration of said injection site by said needle to a penetration depth defined by engagement of said cassette housing element with said forward base element of said reusable driving assembly.
 10. An automatic injection device according to claim 9 and wherein: following injection, said disposable cassette assembly extends partially outside of said reusable driving assembly at said forward injection end and is releasably retained in said reusable driving assembly; and said disposable cassette assembly may thereafter be fully disengaged from said reusable driving assembly by axially pulling said disposable cassette assembly out of said reusable driving assembly.
 11. An automatic injection device according to claim 9 and wherein only following insertion and retention of said disposable cassette assembly in said reusable driving assembly, said automatic injection device may be caused to assume said needle insertion operative orientation by pressing said trigger button element, thereby causing forward axial displacement of said cassette housing element and resulting penetration of said injection site by said needle.
 12. An automatic injection device according to claim 8 and wherein said reusable driving assembly includes a plunger element, a forward cover element and a rearward cover element, a spring and at least one cocked orientation retaining element operative in a cocked operative orientation of said reusable driving assembly for cocking said plunger element against an urging of said spring and retaining said plunger element in said cocked operative orientation.
 13. An automatic injection device comprising: a reusable driving assembly having a rearward end and a forward injection end, said reusable driving assembly arranged along a longitudinal axis extending through both said rearward end and said forward injection end; and a disposable cassette assembly; wherein: said disposable cassette assembly is removably insertable into said reusable driving assembly at said forward injection end, such that at least a portion of said disposable cassette assembly protrudes forwardly from said forward injection end to a first longitudinal extent; following injection, said disposable cassette assembly extends forwardly from said forward injection end to a second longitudinal extent, which is greater than the first longitudinal extent and is releasably retained in said reusable driving assembly; and said disposable cassette assembly may thereafter be fully disengaged from said reusable driving assembly by axially pulling said disposable cassette assembly out of said reusable driving assembly to along said longitudinal axis, and wherein: said reusable driving assembly includes a trigger button element; said disposable cassette assembly includes a cassette housing element, a needle and an injectable liquid to be injected at an injection site; only following insertion and retention of said disposable cassette assembly in said reusable driving assembly, said automatic injection device may be caused to assume a needle insertion operative orientation by pressing said trigger button element, thereby causing forward axial displacement of said cassette housing element and resulting penetration of said injection site by said needle.
 14. An automatic injection device according to claim 13 wherein said reusable driving assembly includes a plunger element, a forward cover element and a rearward cover element, a spring and at least one cocked orientation retaining element operative in a cocked operative orientation of said reusable driving assembly for cocking said plunger element against an urging of said spring and retaining said plunger element in said cocked operative orientation.
 15. An automatic injection device according to claim 14 and wherein said forward cover element and said rearward cover element move towards each other before said reusable driving assembly assumes said cocked operative orientation and when said reusable driving assembly assumes said cocked operative orientation, said forward cover element and said rearward cover element are locked against mutual axial displacement.
 16. An automatic injection device according to claim 14 and wherein: said disposable cassette assembly includes a prefilled syringe including said needle for injecting said injectable liquid at said injection site and a needle guard element, and following injection and removal of said needle from the injection site, assumption of said cocked operative orientation of said reusable driving assembly is possible thereafter only following forward displacement of said needle guard element relative to said needle.
 17. An automatic injection device according to claim 13 and wherein: said reusable driving assembly includes a safety catch element; and said automatic injection device may be caused to assume a needle insertion operative orientation by pressing said trigger button element, thereby causing forward axial displacement of said cassette housing element and resulting penetration of said injection site by said needle, only when all of the following conditions are met: said reusable driving assembly is in a cocked operative orientation; said disposable cassette assembly is inserted and retained in said reusable driving assembly, and said safety catch element is in a disengaged operative orientation.
 18. An automatic injection device according to claim 17 and wherein said automatic injection device may be caused to assume said needle insertion operative orientation by pressing said trigger button element, thereby causing forward axial displacement of said cassette housing element and resulting penetration of said injection site by said needle, only when all of the following conditions are met: said reusable driving assembly is in said cocked operative orientation; and thereafter said disposable cassette assembly is fully inserted and retained in said reusable driving assembly, and thereafter said safety catch element is in said disengaged operative orientation. 